Nimona's entire stick is transforming. Lots of her problems come from transforming. Lot's of her solutions come from transforming. What is Nimona's main power? Staying still and doing what she is told. No it's transforming lmao.

Nimona is introduced with very similar identifiers of being queer (pink hair, haircut, clothing) it isn't very subtle, nor does it matter because it is only one form. The only identifier that we get throughout the film that Nimona is a particular animal is the color pink - which in certain scenes, we are reminded is a choice.

She is violently persecuted because she can shapeshift, nearly to the point of suicide. Sound familiar? She could not shapeshift, but to her, that is basically the same thing as dying. Then she does, and she is "free". It is a rather blunt analogy for gender dysphoria & transitioning.

What is Nimona's gender? Does a fear have a gender? She's closer to a primordial force than a human, but she still shows a preferred form. But it isn't static. She is explicitly non binary.

People relate to the film because it demonstrates feelings that are similar to the situations that they go through, not because it demonstrates the exact situation that they are in. There are other reads, but this is a prominent one. Much like Celeste, the source material was written without an explicit understanding of what these feelings were - it is only with hindsight (this film) that these reasons are spelled out more clearly.

Further reading: https://time.com/6291748/nimona-shape-shifting-trans/