It can be found on the crystal crags biome. There was a bug in the early acces version of the game which made it impossible for certain things to spawn or to be obtained. It affected items and creatures mostly. From what I see this bug is still persist in the final version of the game. If you can't find it on the crystal biome then I think it is possible that this bug is the cause of it.
+RYAN HAYCOCK from the crystal crags biome but the chance of finding it depends on how big your world is, in Huge worlds there will be more chance finding it
I can't remember all of them, but one can be found on the floating fortresses above the clouds. It's on the forest biome if I'm correct, use skydive in the menu to get on it.