As I've said before, we don't have a ton of "kid" specific kitchen tools, but there are a few items of kitchen gear that I've found to be really handy for involving toddlers in cooking. We were given a little whisk, but it turned out to be too delicate for my toddler's energetic style, so we bought one of these super sturdy potato mashers after seeing one in a friend's kitchen. You can use it for all sorts of things like mixing eggs for scrambling, mixing up muffin batter, stirring together popsicle mixtures, mashing beans for hummus, mixing flours for bread making, and yes, mashing potatoes. It's a favorite.
Check out this masher here.