Funny story....won't help you, but thought I'd share anyway.
My ex mother in law is a primary school teacher and had to do exactly the same as you, buy stocking fillers for same aged children, so off she popped to Manchester centre. After several hours of wandering round without success she ended up in China town and had a look in a shop there which had little rubber chimps for sale. As they'd recently done a class project on monkeys, she thought it'd be a good idea to buy these chimps which were wrapped in cellophane.
It wasn't till the day after these chimps were given to the children( and parents were storming the school in outrage) that she realised that perhaps they weren't the best of ideas..........
If you squeezed their stomachs............out popped a penis on each and every one of them!!!!