Superlative form of squatty: most squatty.(adjective)
Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License
Use "squattiest" in a sentence
"Note that I am easily the happiest person in the photo, and definitely the squattiest."
"On one of these points a large, broad-nosed hippo was standing, looking as shapeless as if it had been roughly modelled in mud, and set upon four legs of the shortest and squattiest kind."