Monsters!
I love these Monster Paper Cups, we've done them a few years now. There is a whole rainbow of paper cups available. I usually put holes in each side for the arms, which look effective with either one or two pipe cleanes through. If the mums pull the arms down and give a twist in the middle then it stops the toddlers pulling the arms straight out.
Decorate with coloured spots, sticky backed foam mouths and different sized eye stickers.
Since our original paper cup crafts, we have made lots more variations, they are simple, loads of fun and go down really well with the parents and toddlers a like.
Here are some links to some more of paper cup crafts: