One blink and he's gone like a professional thief! Where did he even go?!

"Huh! Didn't wait long to ditch me, the jerk! Who needs him?!"

This is both legitimate acting in case they are being watched from the shadows, and a genuine gripe because Popp is rather sensitive about being left behind. He skulks and crunches his way through the forest, muttering about how he's a powerful mage who doesn't need backup.

...Mithrun wouldn't ditch him for real, right?