Sharks vs. Superheroes
This was Eddie's birthday party last year. He couldn't choose between the two, so we combined two themes into one. The kids painted with Kool-aid and ice cubes, which was a big hit. We had shark balloons in a kiddie pool they were supposed to sit on to pop (tip: get cheap balloons or little kids won't be able to pop them!). For the favors, I made each kid a felt super hero mask and we provided cans of shark repellent (silly string).
Eddie went through a robot phase earlier this year, so I started collecting ideas for a robot party just in case. We did build our own robot out of things we had around the house for his Valentine box, which turned out great. PBS Kids has a great tutorial on making Tin Can Robots, which could be a fun activity for a party with a couple of adults manning the hot glue guns. You can find a lot of cute robot cakes on Pinterest, but my favorite was this one from Cakes by Becky.
Skeletons
This is the theme that Eddie chose for this year. Skeletons are a little hard to find in May, but luckily we're not having a big party this year. I love this 3-D skeleton cake pan from Wilton. I plan to do a similar cake, but not 3-D, just using a rectangular pan and cutting the cake into coffin shape. If you have enough people at your party to form teams, the Mr. Bones Relay Race could be a fun and easy game to put together. I might make one or two anyway because Eddie loves skeletons (he's a self-proclaimed skeleton expert), so I'm sure they would be well used at our house.