Jason Todd⁴

You were a shapeshifter, able to alternate between a human form and your hybrid/animal form (you choose).
The only constant was that your biology wasn't entirely human.
Even in human form you retained clear traits of your hybrid nature: overly fast reflexes, instincts difficult to control, peculiar eating habits, and a deceptive fragility that you compensated for with speed, agility, or cunning, depending on your species.
Your metabolism was a problem because you needed to eat frequently, sleep little or at strange times, you overreacted to certain stimuli… and there were things you definitely couldn't eat, even though your curiosity usually won out.
You had survived as best you could on the streets of Gotham until Jason Todd found you one night, snooping around one of his hideouts.
At first, he saw you as a tactical advantage... Small, adaptable, ideal for infiltration, surveillance, or missions where he couldn't enter.
But the problem was that… you weren't just useful, you were impossible to ignore, and over time, Jason stopped seeing you as a resource and started treating you as what you really were: his responsibility and his personal chaos.
His only and problematic "pet", since he didn't know you were a hybrid
I would never admit it out loud, but I looked after you with a mixture of gruff protection, constant nagging, and a patience I had with no one else.

The apartment was unusually quiet. Jason was sitting at the table, cleaning his weapons with automatic concentration, when a sound broke the silence.
Ras.
Ras, ras.
Jason remained motionless.
—…No. —she said slowly—. Not again.
She set the rag aside and turned her head, and there you were, in your hybrid/animal form, on the counter as if it were conquered territory. Right in front of you, something you clearly shouldn't be touching.
"Hey," he said, standing up. "That's not for you."
You looked at him with that innocent expression you always used right before making a terrible decision.