What is this kid's name?

Yesterday, I overheard during our walk...

"HIEFER, stay with your brother!" Mom shouted.

(That can't be right...)

"HYPER! HYPER get on the sidewalk!"

(Still can't be right. But this is Utah any word, sound, stringing together of letters will do.)

"HAPPIER! Get on that sidewalk! Now, HOPPIER!" (as in a happy bunny?)

(No, still a no go. Definitely something that end in -per. All I've come up with is Piper, but that doesn't cover the "H" sound at the beginning. Crazy lady.)

Any ideas?