diff --git a/src/main/java/org/cactoos/collection/HeadOf.java b/src/main/java/org/cactoos/collection/HeadOf.java
index 061521555b..c39196ecbc 100644
--- a/src/main/java/org/cactoos/collection/HeadOf.java
+++ b/src/main/java/org/cactoos/collection/HeadOf.java
@@ -40,31 +40,31 @@ public final class HeadOf<T> extends CollectionEnvelope<T> {
 
     /**
      * Ctor.
-     * @param skip How many to skip
+     * @param num Number of head elements
      * @param src Source elements
      */
     @SafeVarargs
-    public HeadOf(final int skip, final T... src) {
-        this(skip, new IterableOf<>(src));
+    public HeadOf(final int num, final T... src) {
+        this(num, new IterableOf<>(src));
     }
 
     /**
      * Ctor.
-     * @param skip How many to skip
+     * @param num Number of head elements
      * @param src Source iterable
      */
-    public HeadOf(final int skip, final Iterable<T> src) {
-        this(skip, new CollectionOf<T>(src));
+    public HeadOf(final int num, final Iterable<T> src) {
+        this(num, new CollectionOf<T>(src));
     }
 
     /**
      * Ctor.
-     * @param skip How many to skip
+     * @param num Number of head elements
      * @param src Source collection
      */
-    public HeadOf(final int skip, final Collection<T> src) {
+    public HeadOf(final int num, final Collection<T> src) {
         super(() -> new CollectionOf<T>(
-            new org.cactoos.iterable.HeadOf<T>(skip, src)
+            new org.cactoos.iterable.HeadOf<T>(num, src)
         ));
     }
 
diff --git a/src/main/java/org/cactoos/collection/TailOf.java b/src/main/java/org/cactoos/collection/TailOf.java
index eb84c4d382..d304ec3f41 100644
--- a/src/main/java/org/cactoos/collection/TailOf.java
+++ b/src/main/java/org/cactoos/collection/TailOf.java
@@ -40,31 +40,31 @@ public final class TailOf<T> extends CollectionEnvelope<T> {
 
     /**
      * Ctor.
-     * @param skip How many to skip
+     * @param num Number of tail elements
      * @param src Source elements
      */
     @SafeVarargs
-    public TailOf(final int skip, final T... src) {
-        this(skip, new IterableOf<>(src));
+    public TailOf(final int num, final T... src) {
+        this(num, new IterableOf<>(src));
     }
 
     /**
      * Ctor.
-     * @param skip How many to skip
+     * @param num Number of tail elements
      * @param src Source iterable
      */
-    public TailOf(final int skip, final Iterable<T> src) {
-        this(skip, new CollectionOf<T>(src));
+    public TailOf(final int num, final Iterable<T> src) {
+        this(num, new CollectionOf<T>(src));
     }
 
     /**
      * Ctor.
-     * @param skip How many to skip
+     * @param num Number of tail elements
      * @param src Source collection
      */
-    public TailOf(final int skip, final Collection<T> src) {
+    public TailOf(final int num, final Collection<T> src) {
         super(() -> new CollectionOf<T>(
-            new org.cactoos.iterable.TailOf<T>(skip, src)
+            new org.cactoos.iterable.TailOf<T>(num, src)
         ));
     }
 }
diff --git a/src/main/java/org/cactoos/iterable/HeadOf.java b/src/main/java/org/cactoos/iterable/HeadOf.java
index aabbec2fa8..7aaf84b21b 100644
--- a/src/main/java/org/cactoos/iterable/HeadOf.java
+++ b/src/main/java/org/cactoos/iterable/HeadOf.java
@@ -37,23 +37,22 @@ public final class HeadOf<T> extends IterableEnvelope<T> {
 
     /**
      * Ctor.
-     * @param skip How many to skip
+     * @param num Number of head elements
      * @param src The underlying iterable
      */
     @SafeVarargs
-    public HeadOf(final int skip, final T... src) {
-        this(skip, new IterableOf<>(src));
+    public HeadOf(final int num, final T... src) {
+        this(num, new IterableOf<>(src));
     }
 
     /**
      * Ctor.
-     * @param skip Count skip elements
+     * @param num Number of head elements
      * @param iterable Decorated iterable
      */
-    public HeadOf(final int skip, final Iterable<T> iterable) {
+    public HeadOf(final int num, final Iterable<T> iterable) {
         super(() -> () -> new org.cactoos.iterator.HeadOf<>(
-            skip, iterable.iterator()
+            num, iterable.iterator()
         ));
     }
-
 }
diff --git a/src/main/java/org/cactoos/iterable/TailOf.java b/src/main/java/org/cactoos/iterable/TailOf.java
index 8a3879074b..099d7d278a 100644
--- a/src/main/java/org/cactoos/iterable/TailOf.java
+++ b/src/main/java/org/cactoos/iterable/TailOf.java
@@ -37,22 +37,22 @@ public final class TailOf<T> extends IterableEnvelope<T>  {
 
     /**
      * Ctor.
-     * @param skip How many to skip from the bootm
+     * @param num Number of tail elements
      * @param src The underlying iterable
      */
     @SafeVarargs
-    public TailOf(final int skip, final T... src) {
-        this(skip, new IterableOf<>(src));
+    public TailOf(final int num, final T... src) {
+        this(num, new IterableOf<>(src));
     }
 
     /**
      * Ctor.
-     * @param skip Count skip elements
+     * @param num Number of tail elements
      * @param iterable Decorated iterable
      */
-    public TailOf(final int skip, final Iterable<T> iterable) {
+    public TailOf(final int num, final Iterable<T> iterable) {
         super(() -> () -> new org.cactoos.iterator.TailOf<>(
-            skip, iterable.iterator()
+            num, iterable.iterator()
         ));
     }
 }
diff --git a/src/main/java/org/cactoos/iterator/HeadOf.java b/src/main/java/org/cactoos/iterator/HeadOf.java
index 3178bf5e0e..e4b68690f6 100644
--- a/src/main/java/org/cactoos/iterator/HeadOf.java
+++ b/src/main/java/org/cactoos/iterator/HeadOf.java
@@ -44,27 +44,29 @@ public final class HeadOf<T> implements Iterator<T> {
     private final Iterator<T> origin;
 
     /**
-     * Count skip elements.
+     * Number of head elements.
      */
-    private int omit;
+    private final int head;
+
+    /**
+     * Current element index.
+     */
+    private int current;
 
     /**
      * Ctor.
      * @param iterator Decorated iterator
-     * @param skip Count skip elements
+     * @param num Num of head elements
      */
-    public HeadOf(final int skip, final Iterator<T> iterator) {
+    public HeadOf(final int num, final Iterator<T> iterator) {
         this.origin = iterator;
-        this.omit = skip;
+        this.head = num;
+        this.current = 0;
     }
 
     @Override
     public boolean hasNext() {
-        while (this.omit > 0 && this.origin.hasNext()) {
-            this.origin.next();
-            --this.omit;
-        }
-        return this.origin.hasNext();
+        return this.current < this.head && this.origin.hasNext();
     }
 
     @Override
@@ -74,6 +76,7 @@ public T next() {
                 "The iterator doesn't have items any more"
             );
         }
+        ++this.current;
         return this.origin.next();
     }
 }
diff --git a/src/main/java/org/cactoos/iterator/TailOf.java b/src/main/java/org/cactoos/iterator/TailOf.java
index 95c0ca4de2..bc9e69a845 100644
--- a/src/main/java/org/cactoos/iterator/TailOf.java
+++ b/src/main/java/org/cactoos/iterator/TailOf.java
@@ -39,31 +39,35 @@
 public final class TailOf<T> implements Iterator<T> {
 
     /**
-     * Reversed iterator.
+     * Decorated iterator.
      */
-    private final Iterator<T> reversed;
+    private final Iterator<T> origin;
 
     /**
      * Ctor.
      * @param iterator Decorated iterator
-     * @param skip Count skip elements
+     * @param num Number of tail elements
      */
-    public TailOf(final int skip, final Iterator<T> iterator) {
-        this.reversed = new HeadOf<>(
-            skip,
-            new LinkedList<>(
-                new CollectionOf<>(iterator)
-            ).descendingIterator()
-        );
+    public TailOf(final int num, final Iterator<T> iterator) {
+        this.origin = new LinkedList<>(
+            new CollectionOf<>(
+                new HeadOf<>(
+                    num,
+                    new LinkedList<>(
+                        new CollectionOf<>(iterator)
+                    ).descendingIterator()
+                )
+            )
+        ).descendingIterator();
     }
 
     @Override
     public boolean hasNext() {
-        return this.reversed.hasNext();
+        return this.origin.hasNext();
     }
 
     @Override
     public T next() {
-        return this.reversed.next();
+        return this.origin.next();
     }
 }
diff --git a/src/test/java/org/cactoos/collection/HeadOfTest.java b/src/test/java/org/cactoos/collection/HeadOfTest.java
index dda010b478..48096e4ff8 100644
--- a/src/test/java/org/cactoos/collection/HeadOfTest.java
+++ b/src/test/java/org/cactoos/collection/HeadOfTest.java
@@ -24,7 +24,6 @@
 
 package org.cactoos.collection;
 
-import org.cactoos.iterable.IterableOf;
 import org.hamcrest.MatcherAssert;
 import org.hamcrest.Matchers;
 import org.junit.Test;
@@ -35,92 +34,23 @@
  * @version $Id$
  * @since 0.29
  * @checkstyle JavadocMethodCheck (500 lines)
+ * @checkstyle MagicNumberCheck (500 lines)
  */
 public final class HeadOfTest {
 
     @Test
     @SuppressWarnings("PMD.AvoidDuplicateLiterals")
-    public void skipIterable() throws Exception {
+    public void headCollection() throws Exception {
         MatcherAssert.assertThat(
             "Can't skip elements in iterable",
             new HeadOf<>(
-                2,
-                new IterableOf<>("one", "two", "three", "four")
-            ),
-            Matchers.contains(
-                "three",
-                "four"
-            )
-        );
-    }
-
-    @Test
-    @SuppressWarnings("PMD.AvoidDuplicateLiterals")
-    public void skipArray() throws Exception {
-        MatcherAssert.assertThat(
-            "Can't skip elements in array",
-            new HeadOf<>(
-                2,
-                "one", "two", "three", "four"
-            ),
-            Matchers.contains(
-                "three",
-                "four"
-            )
-        );
-    }
-
-    @Test
-    @SuppressWarnings("PMD.AvoidDuplicateLiterals")
-    public void skipCollection() throws Exception {
-        MatcherAssert.assertThat(
-            "Can't skip elements in collection",
-            new HeadOf<>(
-                2,
-                new CollectionOf<>("one", "two", "three", "four")
-            ),
-            Matchers.contains(
-                "three",
-                "four"
-            )
-        );
-    }
-
-    @Test
-    public void skippedAllElements() throws Exception {
-        MatcherAssert.assertThat(
-            "Can't skip all elements",
-            new HeadOf<>(
-                2,
-                "one", "two"
-            ),
-            Matchers.empty()
-        );
-    }
-
-    @Test
-    public void skippedMoreThanExists() throws Exception {
-        MatcherAssert.assertThat(
-            "Can't skip more than exists",
-            new HeadOf<>(
-                Integer.MAX_VALUE,
-                "one", "two"
-            ),
-            Matchers.empty()
-        );
-    }
-
-    @Test
-    @SuppressWarnings("PMD.AvoidDuplicateLiterals")
-    public void skippedNegativeSize() throws Exception {
-        MatcherAssert.assertThat(
-            "Can't process negative skipped size",
-            new HeadOf<>(
-                -1,
+                3,
                 "one", "two", "three", "four"
             ),
             Matchers.contains(
-                "one", "two", "three", "four"
+                "one",
+                "two",
+                "three"
             )
         );
     }
diff --git a/src/test/java/org/cactoos/collection/TailOfTest.java b/src/test/java/org/cactoos/collection/TailOfTest.java
index d40271cb2d..8d1b4802cb 100644
--- a/src/test/java/org/cactoos/collection/TailOfTest.java
+++ b/src/test/java/org/cactoos/collection/TailOfTest.java
@@ -47,8 +47,8 @@ public void tailCollection() throws Exception {
                 "one", "two", "three", "four"
             ),
             Matchers.contains(
-                "two",
-                "one"
+                "three",
+                "four"
             )
         );
     }
diff --git a/src/test/java/org/cactoos/iterable/HeadOfTest.java b/src/test/java/org/cactoos/iterable/HeadOfTest.java
index 1033398b91..eab887254c 100644
--- a/src/test/java/org/cactoos/iterable/HeadOfTest.java
+++ b/src/test/java/org/cactoos/iterable/HeadOfTest.java
@@ -38,7 +38,7 @@ public final class HeadOfTest {
 
     @Test
     @SuppressWarnings("PMD.AvoidDuplicateLiterals")
-    public void skipIterable() throws Exception {
+    public void headIterable() throws Exception {
         MatcherAssert.assertThat(
             "Can't skip elements in iterable",
             new HeadOf<>(
@@ -47,8 +47,8 @@ public void skipIterable() throws Exception {
                 )
             ),
             Matchers.contains(
-                "three",
-                "four"
+                "one",
+                "two"
             )
         );
     }
diff --git a/src/test/java/org/cactoos/iterable/TailOfTest.java b/src/test/java/org/cactoos/iterable/TailOfTest.java
index 01cd138593..3c00a2582a 100644
--- a/src/test/java/org/cactoos/iterable/TailOfTest.java
+++ b/src/test/java/org/cactoos/iterable/TailOfTest.java
@@ -33,6 +33,7 @@
  * @version $Id$
  * @since 0.30.1
  * @checkstyle JavadocMethodCheck (500 lines)
+ * @checkstyle MagicNumberCheck (500 lines)
  */
 public final class TailOfTest {
 
@@ -42,12 +43,13 @@ public void tailIterable() throws Exception {
         MatcherAssert.assertThat(
             "Can't get tail portion of iterable",
             new TailOf<>(
-                2,
+                3,
                 "one", "two", "three", "four"
             ),
             Matchers.contains(
                 "two",
-                "one"
+                "three",
+                "four"
             )
         );
     }
diff --git a/src/test/java/org/cactoos/iterator/HeadOfTest.java b/src/test/java/org/cactoos/iterator/HeadOfTest.java
index 1d5a1e364a..f3babf3c6a 100644
--- a/src/test/java/org/cactoos/iterator/HeadOfTest.java
+++ b/src/test/java/org/cactoos/iterator/HeadOfTest.java
@@ -35,6 +35,7 @@
  * @version $Id$
  * @since 0.8
  * @checkstyle JavadocMethodCheck (500 lines)
+ * @checkstyle MagicNumberCheck (500 lines)
  */
 public final class HeadOfTest {
 
@@ -50,16 +51,41 @@ public void headIterator() throws Exception {
                 ).iterator()
             ),
             Matchers.contains(
-                "three",
-                "four"
+                "one",
+                "two"
             )
         );
     }
 
+    @Test
+    public void returnsIntactIterator() throws Exception {
+        MatcherAssert.assertThat(
+            new LengthOf(
+                new HeadOf<>(
+                    3,
+                    new IterableOf<>(
+                        "one", "two"
+                    ).iterator()
+                )
+            ).intValue(),
+            Matchers.equalTo(2)
+        );
+    }
+
+    @Test(expected = NoSuchElementException.class)
+    public void returnsEmptyIterator() throws Exception {
+        new HeadOf<>(
+            0,
+            new IterableOf<>(
+                "one", "two"
+            ).iterator()
+        ).next();
+    }
+
     @Test(expected = NoSuchElementException.class)
-    public void errorSkippedMoreThanExists() throws Exception {
+    public void emptyIteratorForNegativeSize() throws Exception {
         new HeadOf<>(
-            2,
+            -1,
             new IterableOf<>(
                 "one", "two"
             ).iterator()
diff --git a/src/test/java/org/cactoos/iterator/TailOfTest.java b/src/test/java/org/cactoos/iterator/TailOfTest.java
index 17f2b127ff..e0a058334f 100644
--- a/src/test/java/org/cactoos/iterator/TailOfTest.java
+++ b/src/test/java/org/cactoos/iterator/TailOfTest.java
@@ -35,6 +35,7 @@
  * @version $Id$
  * @since 0.30.1
  * @checkstyle JavadocMethodCheck (500 lines)
+ * @checkstyle MagicNumberCheck (500 lines)
  */
 public final class TailOfTest {
 
@@ -50,16 +51,41 @@ public void tailIterator() throws Exception {
                 ).iterator()
             ),
             Matchers.contains(
-                "two",
-                "one"
+                "three",
+                "four"
             )
         );
     }
 
+    @Test
+    public void returnsIntactIterator() throws Exception {
+        MatcherAssert.assertThat(
+            new LengthOf(
+                new TailOf<>(
+                    3,
+                    new IterableOf<>(
+                        "one", "two"
+                    ).iterator()
+                )
+            ).intValue(),
+            Matchers.equalTo(2)
+        );
+    }
+
+    @Test(expected = NoSuchElementException.class)
+    public void returnsEmptyIterator() throws Exception {
+        new TailOf<>(
+            0,
+            new IterableOf<>(
+                "one", "two"
+            ).iterator()
+        ).next();
+    }
+
     @Test(expected = NoSuchElementException.class)
-    public void errorSkippedMoreThanExists() throws Exception {
+    public void emptyIteratorForNegativeSize() throws Exception {
         new TailOf<>(
-            2,
+            -1,
             new IterableOf<>(
                 "one", "two"
             ).iterator()