Answer:
I know a word of letters three. Add two, and fewer there will be!
I usually wear a yellow coat. I usually have a dark head. I make marks wherever I go.
I sleep by day, I fly by night. I have no feathers to aid my flight.
I wear a red robe, with staff in hand, and a stone in my throat.
i'm popular for Knuzlocks what am i
This small, round stone fruit that is typically bright or dark red, is often served on top of whipped cream on a milk shake.