Cleave is a funny feat, we all know. I have often felt like it was wasted on creatures though. Do your players get dropped enough that a creature ever gets to use it? I am thinking of replacing the normal Cleave with a monster version, something humanoids cant usually get like multi-attack, so they can cleave just a little more often. How about whenever they do enough damage to do trigger a death from massive damage check? Throw out some ideas!