1. Material to non-permanently stick

Hello everyone,
I am in a bit of a predicament. For a project my team is designing a concept/ that is to be used for children to develop some physical skill. We have come up with a throwing game in which the child throws an object at a board and it sticks. It has been moulded around using 3 animals and their foods as the the throwing object.

We are having a lot of trouble coming up with a 3rd material that can be used to attach the thrown object to the corresponding animal if it is that animals food. If it is the wrong animal then the thrown object falls to the ground.

So far we are going to utilize magnets and velcro but we need a 3rd. The throwing object also needs to be basically identical to the others (eg, covering the outside in the soft velcro side and putting a magnet in only 1) so the kids cannot immediately differentiate what board they through it at.

We did think of using another magnet or discuss the possibility using electromagnets, but adding this will overall complicate the game and also the intended function.

Basically, do you guys know of any non-permanent solution for attaching 2 objects together but can implemented into the design above without much deviation. The object cannot permanently be stuck as the game should be played many times and the corresponding opposite of the solution should be on the board while the other is the thrown object (eg + & - magnet and 2 sides of velcro). We have had suggestions of the a suction cup ball, but this is not keeping the thrown objects distinguishable from each other!
Maybe some of you have come across something that serves this purpose besides these 2 materials.
Any ideas would be great.
Cheers

2. For the third option, can you just reverse the polarity of the magnet? North won't stick to north, etc...