As I recall, it was going to do a physical bleed effect or something to that effect. It sounded appealing
Actually, you are spot on, It was a trap that would root your target in place and apply a bleed affect at the same time. I rejoiced when I found out about it but very sad when they removed it before it went live. The reasoning for the removal was because of our pets would you believe.
The problem was that the Bear trap had a very similar setup to that of a frost nova from a mage. The parameters being that it would break after x amount of damage was done to the target.
The problem that the programers faced was that our pet would still chew on the target whilst it was under the effect of the bear trap compared to the current freezing trap, where ones pet will automatically stop attacking once the trap goes off on the victim.
With the pet still attacking the bear trapped target, it would break very quickly because of the damage done to it. In fact they scrapped the bear trap and then tried to implement the same "target will remain trapped until X amount of damage is done to the target or effects expire" to our Freezing traps a little further down the track, but to no avail. The programmers could still not find an easy way around getting our pet to stop attacking it and was scrapped.