Horseshoe Crab

So, I want to start by stressing I know very little about Marine Biology. It's a passing hobby, and I have never been particularly involved, having not liked science as a child.

But, with Minecraft 1.19 and the introduction of Mangroves into the game, at least partially due to spreading awareness of their importance, I think incorporating a new mob would be interesting, especially one that faces endangerment in the same way as mangroves do: the horseshoe crab.

These guys have been around for aeons. They're also comparatively unknown as creatures, but their blood is critical to a lot of modern science and honestly, they just look super quirky. I think they would make a great addition to the game, because while I concede Minecraft isn't simply a game for advocating for endangered animals, I would say that the Horseshoe crab is significantly less well known than, for example, the axolotl or the polar bear.

Ultimately I think they'd be a cute and fun addition to the otherwise lacking cold water biome, and would allow for an interesting find in mangroves, or deep in the crevices of underwater caves.