Krillin is a chestnut monk iirc. Kuririn クリリン is his actual name.

Like most characters in the series, the name Krillin is a pun. In his case, its Japanese source, Kuririn, is made up of two parts. The first two syllables come from 栗 (kuri), which means "chestnut" in reference to his shaved head (the "chestnut" pun is also carried over to his daughter Marron). The second part of his name comes from 少林 (Shōrin; "Shaolin" in Chinese), as his early character designs were closely modeled on.

Shaolin monks. Other beliefs are that his name comes from kuri-kuri/kurin-kurin (an onomatopoeia for something cute and round), kuri-kuri shita me (meaning "big round eyes"), or the words kurikuri (which can mean "bald") and rin (a word added to the end of a name to make it sound cute). His English name, meanwhile, seems to be a play on "krill" (both a minuscule species of shrimp-like crustacean and the Swedish term for a small fry of fish) in reference to his diminutive stature.

From: https://dragonball.fandom.com/wiki/Krillin/Misc

Which makes me wonder if that isn't his real name, and maybe a nickname given to him by other characters in the show, like from before he first meets Goku in Dragonball. Because other characters have the food or underwear themes of names, yet Krillin's name is fully just making fun of how he looks.

Also isn’t Krillin canonically a duck?

What a majestic creature.

What? When/how/why is krillin a duck?

I just learnt that Oolong was born this way and the other animal people took a drug that turned them into beast people.