But that opens up the question why the first evolutions, the Nidorinos, resemble horned rodents. And then there's the question of why they were the only like to be given a gender-species divide as well.
I always thought the Nidoran's were based on Triceratops, and Nidoking bears a strong resemblance to Armadon from Primal Rage, another bipedal triceratops.
It makes a specific mention of the mustache being iron filings attracted by Probopass' magnetic nose, and using a magnet to draw facial hair with iron filings is what Wooly Willy (and a shitload of other kids' toys) is all about. I don't think magnets or iron filings are involved in Groucho glasses at all, so Wooly Willy is probably a stronger connection.
I don't know if Wooly Willy started the whole iron filings mustache thing, though. I always just thought it was just a... generic toy thing.
I'm not convinced Groucho glasses have anything to do with it...
Groucho glasses consist of a nose, a mustache, huge eyebrows and, most importantly, glasses. Probopass is missing those last two, meaning he has as much in common with Groucho glasses as Mario does. Or as Tom Selleck does.
Let it be publicly known that I apologize for bringing up Probopass. As penance, a bunch of yokai based Pokemon! Yokai are the Japanese equivalent of demons, BTW.
Drowzee (Baku) and the Lotad family (Kappa) have already been brought up. Froslass is another great example. She is based on Yuki-onna, a well known Yokai that is the ghost of a woman who died in a snowstorm. For some reason, she now kills mortals by controlling snowstorms.
Snorunt, on the other hand i sbased on the Zashiki warashi. a type of ghost that inhabits houses and cared for like a child. Part of its name means tatami mat, and may be the reason for Snorunt's "hat". It is also partially based on the Yukinko, a Japanese snow sprite.
The Ninetails family and perhaps the Zorark family are based on the Kitsune.. Kitsune, AKA keatons, are sometimes mischievous, sometimes benevolent fox spirits. Ninetails ability to grow more tails as it grows older is based explicitly on Kitsune.
Shiftry are based on tengu. Tengu are crow demons with big ol' noses and fans for arms. Tengu Man, from Mega Man, is a good example of what one looks like, actually, An interesting note about this family is that it was exclusive to Ruby, whereas the Ludicolo family was exclusive to Sapphire- both based on very well known, popular Yokai (in Japan, at least.)
Not quite Yokai, but the Torchick family is based on the Basan, a fire breathing chicken of Japanese bestiaries. Yeah. Fire breathing chicken.
Jolteon and the Manetric family may be based on Raiju, thunder god Raijin's pet.
Absol is perhaps based on two disparate beasts- the Barghest. a Celtic cat/dog beast that portends doom to those who see it and the and the Kutabe, a white beast that portends doom to those who see it. As in, it tells them about doom.
.Spiritomb is based around the 108 temptations of Buddhism. This is why the number 108 occurs so much with it- it is 108 spirits who gave in to the 108 temptations and were imprisoned in the Odd Keystone for it.
Zigzagoon's family is an aversion- while based on Tanuki, they are based on the factual Racoon Dogs, and not the mythical Tanooki. Wouldn't want to see one of those anyways- giant balls are something I want to keep out of Pokemon, thank you very much.
And lets end on a whimsical note. Snorlax may be based on Totoro. Which would make Munchlax Chu Totoro. I can see it:
Absol is definitely a Kutabe. Its got the bat wing ear thing. I'd say, like 85% of Pokemon are based on something Japanese, which is sort of disappointing because Pokemon is (if not more than Japan) very popular in the west.
Also, I never put two and two together with that whole Snorlax/Munchlax Totoro/baby Totoro thing. That's awesome, and it makes sense because Totoro slept a lot.