Capture it! And bribe it and pet it until it was nice.

WWYDI the giant Rumblebuffin appeared outside your door?

Wonder why I didn't hear or feel him coming.

WWYDI you woke up with Reep standing on your chest and pointing a sword at your face?

Quote Flynn Rider! 😀 "Well I hope you're here to apologize!"

WWYDI Susan offered to let you borrow one of her really pretty dresses?

That... was a brilliant answer. Just putting that out there. 😆
Uh, take it, duh. 😀

WWYDI Reep cornered you for stealing an orange?

Pull out another Flynn quote. "What? I bought it! Most of it."

WWYDI you accidentally knocked Peter's sword overboard?

I think someone's been watching Tangled.... 😛
Panic.

WWYDI you had to spend the summer at pre-dragon Eustace's?

I'd try to find a painting of a ship so that we could go on an adventure in Narnia where he would turn into a dragon and then change back, but as a nicer person. 😉

WWYDI you met a star?

Ask he/she what it's like!

WWYDI the Eastern Ocean suddenly dried up?

First, I'd revert into a cartoon character and have ❗ over my head.
Then make this face: 😯
Then this face: 😮
Then pull a Boromir and ask, "What new devilry is this?"

WWYDI you were present when Caspian got information/stories about the Eastern Ocean from the old salts?

Make a funny face like this :geek: and walk away.

WWYDI you were bringing a silver apple back to Aslan, but you lost it right before you were about to present it to him?

Probably try to look for it. Maybe even go all the way back to the garden to get another one.

WWYDI Narnia got internet?

Ahahahahaha!!! Follow all of the character's blogs/facebook/twitter/whatever (because I don't even have any of those!) That is also the question that inspired my very, very silliest fanfiction. 😛

WWYDI you were Peter and Narnia got internet and your siblings were urging you to make a facebook page?

They wouldn't have to convince me. I'd just be sure to make sure I set up the fb account under a fake name so RL friends can't hound me. 😀 (they still want me to make a real fb account)
WWYDI you found out that the Friends of Narnia were actually a musical group?

Find out when they're playing and go see them!

WWYDI Edmund asked you to give a speech at his birthday party?

Be ecstatic and frantically try to decide what to say.

WWYDI you had to confront a centaur, alone?