I don't mind animal mascots, I just think the ones with 'tude are facepalm-worthy, like they really thought that thing was "Cool" and "Hip", give me a break...
I like the ones that are either cute like Ristar (technically not an animal, which kinda helps in my book) or at least don't act all "2 Kewl 4 Skewl" like the opossum from Rocket Knight Adventures (he got a bit worse in Sparkster though, but not as bad on the SNES version) and Crash at least has a cartoony goofiness to him, I don't mind goofy mascots either, if they're legitimately funny I'm all the more welcoming to them! Bonk would fit into this goofy category...
Mario doesn't fit into any of these, he's more of a "Silent Protagonist" kinda like most of Nintendo's protagonists, and pretty much remains that way, the only semblance of personality we get from Mario is that he's kinda happy-go-lucky with the "Yahoo"s and "Woohoo"s and all, and that's more than enough to me, you don't need your protagonist to have a personality, you just need them to control well, and that Mario does better than anyone else in gaming, if the character is fun to play as, you the player will fill in the blanks... (Unless you have no imagination)
Honestly, I prefer the more blank-slate protagonists, but that's another conversation entirely...