I really like the names that characters have in FamiTama.
Sheru is how japanese ppl say english "shell", tororo is same thing for "troll" and beru is how they pronounce "bell"

Ahiru is japanese for "duck".
Now that Korokotchi made me wonder where it comes from. Chestnut is "kurin" in japanese, maybe acorn is something like "koroko"?