I was bitten twice by my mangrove. Second time he managed to inject venom. My arm swelled up a bit, and I was a bit nauseous for a day. The fact that I was only tagged twice was a testament to luck. He was SUPER vicious. He would strike at the glass anytime someone walked in the room. Absolute psycho.

As for legality, in California, you need a permit for venomous, but rear fanged appear legal.