Brent is... well, we don't know entirely what Brent is.  I'm sure he knows but he won't be telling us any time soon.

Brent loves Kimberly, Sofia and Tuna and Carrot sandwiches.  Brent hates Brisbane but likes how he tastes.

Brent followed Kimberly home one day and Brisbane wanted him to stay, despite Brent not liking him. 

Brent currently lives with Sofia, since he got increasingly aggressive with Brisbane.