Transcript:
Calvin: Here's the transmogrifier gun. Now try again, and do it right. I want to be a pterodactyl. Hobbes: Ok, here you go. Calvin: Well, now that's more like it! say, when did you turn yourself into a 200-foot-tall colossus? Calvin: I didn't. Why?
Calvin should have been more specific. He should have said, “I want to be a Pteranodon”. He said “pterodactyl”, so Hobbes turned him into a Pterodactylus.