Unique Wild Shape Options

I'm playing in a new 5.5e game starting as a level 5 druid and I"m looking for some unique wild shape options. Ones like the Moorbounder from Explorer's guide to Wild Mount or the Ice Spider Queen from Storm King's Thunder, where they aren't actual animals and only exist in DND. Can you help provide more examples like this so I could potentially have an entire list of unique wild shapes? It can be anything so long as it is a Beast who fits within the wild shape levels and is from any official dnd sourcebook (basically can you buy it on DND beyond).

Giant Fly