Nimona is great LGBT representation, with a queer coded main character and an actual gay relationship. I don't know that its specifically transgender representation, but definitely worth the watch!
Technically not transgender representation since Nimona is a shape-shifting enby creature from the outset and not someone who was assigned a gender at birth and later transitioned away from it, but she does shapeshift into a little beggar boy in one scene so I think it still counts. =3
I consider non-binary identities raised with an enforced binary socialization like myself have every reason to identify as trans. That’s not explicitly displayed in Nimona, but I can confirm that I felt represented and had an incredibly emotional reaction to the film.
Also: there is at least one trans pride flag colors not-so-hidden in the movie. 🏳️⚧️