The pug? It's cute because it's so ugly it shouldn't be, it's the SCIENCE of irrational cuteness, do keep up, sir.
I used to own (and probably still have it somewhere) a dictionary which defined "cute" as "ugly, but appealing" - I had to look it up in about 1990 because I didn't get what people meant by "cute"; this definition helped.
Just to throw a curve-ball, 'cute' also means 'pretending to be clever' and also actually being sharp/ clever. HTF did English develop words with related but contradictory meanings!