Looking at the Gibberling bunch (Lvl 1 brute) in the FRCS, it seems to be that they do the same thing as the Needlefang drake. Although the rules are slightly different, and I think the damage has been adjusted.
Their basic attack is a +4 vs AC that does 3d4+2. But if they reduce 2d4 from the attack, the target is knocked prone.
Another attack, with the same to-hit, does 1d4+1 and knocks the target prone.
Next, they can make attacks of opportunity against adjacent foes that stand up from prone, and they do +2d4 vs. a prone target.
So they are doing the same thing as the Needlefangs (keeping targets down), but it has become a bunch of d4s being thrown around instead of d10s. And while they do 5d4+2 against a prone target, they do not have minor attacks to pull foes down.
Their basic attack is a +4 vs AC that does 3d4+2. But if they reduce 2d4 from the attack, the target is knocked prone.
Another attack, with the same to-hit, does 1d4+1 and knocks the target prone.
Next, they can make attacks of opportunity against adjacent foes that stand up from prone, and they do +2d4 vs. a prone target.
So they are doing the same thing as the Needlefangs (keeping targets down), but it has become a bunch of d4s being thrown around instead of d10s. And while they do 5d4+2 against a prone target, they do not have minor attacks to pull foes down.
