Rabbits were pests anyways so West had no qualms about the task ahead, even if he was sitting there stroking the bunny that he'd grabbed. So that it trusted him and such. And it apparently did since it wasn't fussing and hadn't pooped on him or anything.

Lepus Caput?

West repeated it and eyed the bunny. "Lepus Caput." No wand yet. "Lepus Caput." Easy enough to say. He got his wand out and with one hand put the rabbit on his desk. It flopped around a bit but otherwise seemed content to stay put. Still, West thought that it was a good idea to make sure it didn't get any ideas and run off, so he cast Petrificus Totalus on the rabbit, watching as it stiffened and froze.

Right. Now to make it a hat yes? He stared at the rabbit, trying to picture how his hat would look. Focus was key.