[Cat... cat... Meowth, right? He'll just assume that it's the same thing as with cows and Miltank.]

If Dave's a human [and not an animal that someone's named] then the biggest differences are size and that Dave is bipedal and has hands.

[He's not being intentionally contrary, he's just thinking differently.]

If you call humans people but not animals and plants, then what do you call humans, plants, and animals together?

[He at least recognizes that one of the problems here is that they have different meanings for words.]