DOG ON THE GO by Rachel
"Dog on the Go" is a translational (slide) tessellation. You can tell it's a translational tessellation because the dogs are all at the same angle and facing the same way-- they're simply copied and then moves along the X axis and Y axis, without spinning or flipping.
Is this a tessellation? Well, if we look at the dogs as abstract shapes, then yes, this is a tessellation. However, if we say the shapes are dogs, then we have to ask "Where're the dogs' bodies?" and "Are those things capes, behind the dogs? What're those things above the dogs' necks? Where are the little doggy feet?"
See this example from the "Is it a Tessellation?" section of Tessellations.org for a clearer explanation of why Rachel's dogs make...and don't make...a tessellation.