Ewan was not scared of bunnies. Scared was too mild a word for what he felt. Fear was closer but still did not accurately describe it. People who were afraid still had some control over their bodily functions.
What Ewan felt when he saw a bunny was not fear. It was mind numbing, pee your pants terror.
He could deal with the teeth or the twitchy noses which are scary enough. But the ears really did him in. Those floppy, unnatural ears that were just there listening to everything. It was creepy and Ewan didn't like it one bit.