Eddie Lizzard?

From Discovery Channel:

Male Lizards Disguise as Females to Avoid Attack

Young, male lizards desperate to mate, access women and avoid attack from older
males by pretending to be one of the girls, a new study said.
According to the study published in the Proceedings of the Royal Society B, young male Augrabies flat lizards (Platysaurus broadleyi) hide their colors so as to
imitate plain, brown females.
"In this system the adult males are extremely colorful and extremely territorial and the females are a plain brown," said co-author Scott Keogh, of the School of Biological Sciences at the Australian National University. "Young males purposefully only develop colors on their belly, so they reach sexual maturity by still looking like a female."
Imitating a female allows the juvenile lizards to mate with females, without being detected and driven away by the larger, territorial, adult males, who will chase and bite their young rivals

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See.. for some trannies, it's all about the girls :)