In Minions, we see these little guys evolved naturally, leaving the primordial ocean exactly as they are today. They’ve been on Earth for at least 65 million years, since their first “boss” was a T-Rex.
Yet while they need to attach themselves to bad guys — becoming depressed and listless when they are without a “boss” — they aren’t bad guys, but are generally playful, fun-loving, and good-natured.
In Despicable Me, Coffin, co-director Chris Renaud, and actor Jemaine Clement are credited with providing voices for Tim, Dave, and Jerry respectively. But since then the task of giving these little guys a voice has fallen exclusively on Coffin.