One of the characters is an otter.

You play as an otter.

You play as otters.

You can tame otters and they have multiple uses, like pets or fishing partners.

You can't have an otter as patronus, in fact, you can't have a patronus at all. 0/10

River otters are part of the Odyssey DLC, or can be added via mods. Megalenhydris can be added via mods. It's possible to mount them into battle with mods.

Inclues giant otters and small clawed otters as DLC.

May include otters

Very cute game that might include otters.

Another great fighting game that uses Otter UI.