Meddler's an interesting one - it's one of the weakest T1 heroes on its own but it's one of the strongest if you can cover up the bones sides, which isn't that hard to find a item for.
The bones sides also aren't as bad as they seem. Sure, assuming you only have Burst it takes 4 mana to remove the bones and it only gives you 1 mana, but they don't attack the turn they're summoned. So you can use that mana killing things that are actually going to kill you this turn and deal with the bones later. And when you do, you get a bonus 2 damage killing the bones (assuming something else has been summoned above them). So summoning a bones is really a net loss of 1 damage as a tradeoff for getting to get that damage now and pay it back later.