Scorpid Poison PvP?Follow

There are a few things wrong in what you've heard.

Scorpid poison does not renew stings (that would be a very strange thing).

The poison was nerfed a few patches ago. Before it was possible to have huge poison stacks ticking on your opponent (with standard raid buffs and without tricks 200-300 damage every two seconds where very possible. Playing with your trinkets and timing things right one could achieve poison stacks ticking for a lot more. There are screenshots which show poison stacks ticking for > 800 damage every 2 seconds).
Currently poison does not deal a lot of damage (I believe a full stack ticks for ~100-120 on my scorpid, but those numbers can be way off).

The reason you see a lot of hunters running around with scorpids is PvP.
As viper sting (the one that drains mana) is a poison, a commonn tactic is to send your pet on an opponent you want to mana drain (usually a healer). Apart from the pet interrupting the healer, the poison stack covers your viper sting. If the healer wants to dispel your viper sting, he'll have to dispel the scorpid poison first.
If he does this, he'll waste a lot of mana and global cooldowns on dispelling the poison. If he does not dispel the viper sting, he'll be oom very fast.

I saw a video of a BM hunter on Illidan awhile back with a scorpid that was poison ticking for ~600ish every 2 seconds...probably enraged, but STILL. My god.

Yeah, that video was from before the scorpid poison was nerfed. That was exactly why it was nerfed as well. OP, lovely OP, but still OP.