[dreams]

Aw, you were faster than I. It was so interesting to me that I left it behind spoilers anyway.

Spoiler:

Can change their gender

Clownfish

Spoiler:

In a group of clownfish, there is a strict dominance hierarchy. The largest and most aggressive female is found at the top. Only two clownfish, a male and a female, in a group reproduce through external fertilization. Clownfish are sequential hermaphrodites, meaning that they develop into males first, and when they mature, they become females. If the female clownfish is removed from the group, such as by death, one of the largest and most dominant males will become a female. The remaining males will move up a rank in the hierarchy.

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Is a hermaphrodite
A slug.

Sends out electrical shock