Kids stress heads

Take a balloon, stretch it & fill it with play dough (you can find the recipe I use HERE). I find the easiest way to do this is to cut the spout off a cordial / fizzy pop bottle & stretch the end of the balloon over it, this holds it open nicely for you to poke the play dough through.
When its the size you want tie the end (without the cordial spout in) & hand to the kids to decorate.
Decorating can be done with marker pens, or items glued on. REMEMBER, gluing items on can impede the ability to squish the "stress head", or they might just fall off.

Heres what Zack & Kai came up with (Zacks is on the left, Kai's "Daddy alien, because it has a beard & Moustache" is on the right)