Googoo references the stuff made by some critter that goes by Googoo64. Notables include... a lot. Like Doruge, Sppaman, Magma... there's a pretty sizable list, most high tier, some not. They've all got particularities that tend to make them pretty recognizable after you've seen a few, and they tend to be ridiculous for... varying reasons. It's not uncommon for them to be a treat to watch, though. For all the animation on 'em tends to be... spotty... they can be pretty neat. There's quite a bit of variation between the lot of 'em, honestly. Ninja'd, of course.
Mexican also
tends to imply that the character would be otherwise trash or considerably weaker without their exaggerated qualities, usually because of utterly terrible AI. Th'term's more than a little racist (and also somewhat inaccurate, iirc), and originated, s'far as I'm aware, primarily due to a glut of DBZ (and a couple other series) characters exemplifying the trait (High stats, low programming, general low quality) coming from south/central american countries. And, Salty's chat constituents being what they are, a fair number can't tell spanish from portuguese even if they're repeatedly told something is one or the other and thus everything vaguely spanish sounding (including portuguese and occasionally italian) are/were lumped under "Mexican".
Incidentally, another bar to keep an eye out for is Burst AC (Or... AC Burst, one of the two). They tend to be pretty notable because they spend the betting period beating the everloving hell out of their opponent. The kings and queens of disrespect*, basically, and beyond that tend to have excellent (very aggressive) AI and are overall solid, ranging from pretty solid to incredibly so. Great fun, those critters.
*Disrespect being the AI going bugnuts during the betting period and starting the fight early. Especially glorious is when both sides do you and you get an extra round before the fight