All parallelograms and triangles are examples of these things with order 4, and all examples of these things lead to a tiling of the plane.
All recti able polyominoes are examples of these things. They're not fractals, but the Sierpinski triangle and Gosper island are both examples of these things. Karl Scherer and George Sicherman have discovered pentagonal examples of these things, in addition to the oldest-known pentagonal one, the sphinx. The term for these things was introduced by Simon Golomb as a pun on the name of a certain class of   animals. All parallelograms and triangles are examples of these things with order 4, and all examples of these things lead to a tiling of the plane. For ten points, identify these shapes which can be tiled by identical smaller copies of themselves.
All recti able polyominoes are examples of these things. They're not fractals, but the Sierpinski triangle and Gosper island are both examples of these things.
rep-tiles