What’s a motto with you?

[diamondcutter]

Ms. Todd was wearing a TEAM T-shirt just like Mr. Klutz.
“Why are you both wearing T-shirts that say TEAM?” asked Ryan.
“TEAM is our new motto at Ella Mentry School,” said Mr. Klutz. “It stands for 'Together Everyone Achieves More.’” Mr. Klutz loves initials.
“What’s a motto?” asked Michael.
“Nothing,” said Mr. Klutz. “What’s a motto with you?”
Mr. Klutz laughed even though he didn’t say anything funny. He’s nuts.

Source: Ms. Todd Is Odd, Dan Gutman

Mr. Klutz asks Michael, “What’s a motto with you?” What does he mean? Does he want to know Michael’s motto?

 

[tedmc]

I think it's a cheeky way of saying "What's the matter with you?" Klutz was making fun of Michael's ignorance.

 

[Tarheel]

It's a pun. Admittedly, humor is somewhat subjective, but I think it it's funny. (You have to imagine it being said out loud.)