A small rhombicuboctahedron is one of the 13 Archimedean solids. It has 26 faces (8 equilateral triangles and 18 squares), 48 edges, and 24 vertices.

To create a small rhombicuboctahedron:

1. Take a cube and cut down each of the 4 edges around the cube, leaving a regular octagonal prism. (Imagine a stack of stop signs.)
2. Turn the prism on its side, and make 4 more cuts, just like before.
3. Now take the 8 remaining corners, and cut them off, leaving equilateral triangle faces

A layout of the solid looks like this:

```          +----+
|    |
|    |
+----+    +----+    +----+    +----+
|    | /\ |    | /\ |    | /\ |    | /\
|    |/  \|    |/  \|    |/  \|    |/  \
+----+----+----+----+----+----+----+----+
|    |    |    |    |    |    |    |    |
|    |    |    |    |    |    |    |    |
+----+----+----+----+----+----+----+----+
|    |\  /|    |\  /|    |\  /|    |\  /
|    | \/ |    | \/ |    | \/ |    | \/
+----+    +----+    +----+    +----+
|    |
|    |
+----+
```

This was one of the shapes that Rubik's Snake could be bent into.

A version of this solid where the bottom layer is rotated 45° is called a pseudorhombicuboctahedron or an elongated square gyrobicupola.

Source:
http://mathworld.wolfram.com/SmallRhombicuboctahedron.html