feels like its just strictly worse than Toothy Chest most of the time.
I don't see it that way at all. You can kill toothy chest for free as long as you have a total of 4 attack or more among your minions. You can only kill this for free if you have a single minion with 4 or more attack. Not to mention this costs a full mana less.
My first thought was play this on 2, next turn Inner Rage it into Rampage. And since you have a mana left you could play Abusive Sergeant on it as well! Turn 3, you've got an 11/6 that can attack face, and will be 9/6 after your turn.
Or instead of Sergeant you use Acherus Veteran for a permanent +1 attack making it a turn 3 10/6 minion that is ready to attack.
Or if you have just Marksman, Inner Rage, and Rampage in hand going second you Coin -> Marksmen. Second turn Inner Rage -> Rampage for a 9/6 minion on turn 2!!! Good or not, I'm going to trying to find ways to make this guy work in various decks early on.