Sea urchin

The Sea Urchin (ウニ, Uni) is a type of sea creature introduced in.

In
Upon donating a Sea Urchin to the Museum, it can be found in the large pool in the first room of the Ocean exhibit, along with many other species of sea creature. It is found in the part of the pool closer to the entrance to the saltwater exhibit. The exhibit has this to say about the Sea Urchin:

"Sea urchins are a close relative of both starfish and sea cucumbers and are assumed to be stationary. In actuality, they are capable of walking thanks to their many skinny legs they have between their spikes. They feed on seaweed on the ocean floor using their strong mouths located on their undersides. They are rich in nutrients but also have a lot of cholesterol, so take care not to eat too much."

In
When donating to the museum, Blathers will say the following:

"Ah, the sea urchin...the unabashed goth of the ocean floor! Indeed, with its mane of dark-hued spikes, it looks for all the world as if it might front a punk-rock band. Perhaps its more demure relatives—the sea cucumber and the sea star—disapprove of its outlandish look? 'Twould certainly explain why sea stars gobble up sea urchins every chance they get! But worry not for our spiky friend. Its venomous spines are an effective deterrent to many a predator. And then there are its sticky "tube feet," which it uses to maneuver out of harm's way. TUBE feet, I say! What will this salty rebel think of next?"