In gay slang, otter usually describes a slim to athletically built man with visible body hair. It belongs to the animal taxonomy that grew out of bear culture, and it names a picture rather than a species. Yes. Another animal.
The Taxonomy and Its Limits
Twink, otter, bear, then cub, wolf and chaser. Queer taxonomy gets complicated fast, and no court rules on any of its borders. It grew historically, as a counter-move against one single valid body ideal, and it handed a lot of men their first word for themselves. That is the achievement. The trouble starts when it gets used as a sorting machine: the moment a self-description turns into something assigned to somebody else, the whole usefulness collapses.
A Cultural Label, Not a Body Requirement
Which is exactly the misreading that keeps coming back. TWINK, OTTER, BEAR are cultural labels, not physical entry requirements. Nobody measures a chest or counts hairs at the door. Recognizing yourself in several of these words, or in none of them, means nothing has gone wrong.
Read them loosely in apps too. Self-assessment shifts from city to city, and a man who calls himself an otter in one scene gets filed as a cub in the next. Take the word as a rough hint, never as a description on file.
AT TWINK DEATH
We use the animal names because they're fast and funny, and we treat every one of them as an offer rather than a slot. The rule is short: "Label yourself. Not other people." Naming yourself is voluntary and revocable at any moment. Naming somebody else is simply redundant here, because no category controls who gets in.