The most iconic part of Krookodile is his long, thin snout that looks completely exaggerated from what most crocodile snouts actually look like. Except it's based off of the gharial, and it actually plays DOWN the ridiculous snout a bit, if anything.
The huge, ridiculous magenta, spotted petals of Vileplume are actually real - they're virtually identical to those of Rafflesia arnoldii - even the central pit looks the same. It should also be noted that Rafflesia arnoldii is the largest flower on Earth. Basically, Vileplume SHOULD be a legendary.
The colorful Chatot looks virtually identical to the yellow-collared lovebird (minus the musical note-shaped head). The white coloring around their eyes even gives the appearance of the sclera (white of the eye) on Chatot!