>>38759363Pyukumuku is a combination of "puke" "cucumber", and "mucus", because sea cucumbers expel their innards (in this case in the shape of a hand) to ward off predators, and well, they're slimy.
It's Japanese name is a combination of "sea cucumber" and "fist", for obvious reasons.
As for the "kanji", I wouldn't even say that it's meant to be one, and that the visual similarity is just a good distraction. That was just the best way they could draw a sea cucumber's "mouth" without people going "Hey... is that a..."
