3 Wild Mongrel
There is absolutely no reason to run these outside of a madness engine.
Well, Mongrels can easily, provided they are enchanted with Rancor and/or equipped with a Skullclamp, inflict 7/9 damages, and they're a menace opponent should never understimate: altough suboptimal in a non-madness deck, its controller may be willing to lose a couple of useless cards from hand to keep it alive, so a single burn may not be enough (and it feeds Lavamancers too). Maybe a Keeper Player will think twice before blocking it with an Exalted Angel: if he does Zoo player could kill the Angel, elseway he risks lots of damage. Against deck that use Life as a resource to be spent (Using Skeletal Scryings, Necropotence, Bargain and so on) a single, pumped-up mongrel can be a big problem to deal with.
I repeat, i do admit that it is not the optimal choice, but the simple potential it has is worth at least a chance
Skullclamp in an aggro deck is going to let you trade a useful creature for a bigger hand. And you know what they say, "A beatstick in play is worth two in the hand." (Or something like that, ya know)
That's because you look at Skullclamp and you see a draw engine that kills one of your creatures every time is used.
Just look at it as an empowerment that nets you two cards if the creature dies. Don't be greedy. You don't
have to sac your own creatures to draw cards.
Skullclamp turns a 2/3 kird in a 3/2 that will make you draw if killed (And, as well as Rancor, is a reusable resource). Attack me: shoul I take 3 damages, or block and kill it, knowing you'll easily draw at least another one menace, if not two? "A beatstick going to the graveyard is worth two in the hand."
Obviously, one should know when to use it and when not to and, as I said, not to be greedy: Zoo is not meant to play towards hand size, it has to be a secondary effect. This, of course, leads to the need to run a bunch of 2+ toughness creatures, like said Kirds, Mongrels, Skyshroud Elites, Hidden Gibbons and so on
As usual, my 2 tokencents
