Character Creation Help?!

Hi all!

So this is for a RP offsite on my own forum, but I've been scheming up a character and would love some input and advice!
It's an animal RP, set in a parallel timeline to Earth, where scientists tried to turn animals into weapons of war by splicing their brains with the brains of criminals. Eventually, they were successful in awakening consciousness in the animals but it came with a side effect of increased hyper aggression, so nearly all of the scientists were wiped out.
These animals come equipped with an infectious bite, and when biting another animal was meant to awaken them as well and turn them to the side of war; but rather than that, the animals gained consciousness but without the aggression. These are Hellions vs Paragons, and we play as them! Both of these two different ideals are able to develop different physical mutations, along with various different powers.

My character, Riven, is a black Maned Wolf with ram horns. He also has bioluminescent spots, venom, a hyper heightened sense of smell, and the ability to have a psychic connection with one other character. I haven't found a partner for that yet, but eventually, it'll play a huge part in his characterization. He's selfish, arrogant, self-serving, sly, abrasive, and a bit impulsive. Again, he's a new character and I haven't really fine-tuned him much.
So I guess I'd like some help with that, if anyone has any cool quirks or ideas to make him interesting?

As far as physical quirks go I've got;
- Maned Wolves are tall and lanky, so he's probably a bit top-heavy from the horns so he suffers from neck pain and sits with a slouch.

- His bioluminescent spots vaguely reflect his mood, change colors dependant on fear, stress, excitement, etc.

Some personality quirks might be fun too! I'm notoriously awful in my community for coming up with character concepts, it usually takes me a few weeks to get something I'm truly content with committing to 
I'd love for him to start like... an inter-group group almost too. I've thought of bounty hunting in return for things he might want, but I'm not entirely sure about that. Someone has done a trading business in the past, and the last thing I want to do is be a copy cat since it was such a successful and popular plotting device.

Any ideas or questions are welcome!!!