A terrarium sounds neat! (Sorry about the HOA though, and sardines stink). There are lots of cool plants you could put in the terrarium. Have you ever seen mudskippers? I think they're very fun. You could build a mudskipper oasis, and add different levels with may different types of rocks and plants. That would require a fish tank. If you want to build only a terrarium, there are many ways to do so. Some can be found ready to be filled on Amazon. Or watch YouTube to get different ideas.
