There are lots of cool things you can do as special starting powers:
-Elemental Golem: Air, Fire, Water, Earth...metal, etc...player can switch between them and gain different properties. Each form is weak versus something and strong vs another, it takes a turn to switch and you have limited switches according to a cooldown or energy bar.
-Living Statue: Can solidify at will and be super hard to kill, but also cannot move or attack until re-animating.
-Druid: Sticking with the shape shifting, a druid that changes into different animals is tried and true. Wow has a Druid class that can go Bear (high defense), Panther (high attack, stealth too) etc...
-Lycanthrope: I always like the idea of a werewolf class that is weak as a human but can turn into a werewolf at night and own. And you can choose when you create the class what kind of Lycanthrope you want to be, wereboar, werehawk, werebear, etc...There's a 7DRL in there for sure.
-Halflings: if they stand still cannot be detected by baddies. Ninjas are similar. Maybe it takes a few turns, and no bad guys can be around, but standing still will turn you invisible.
-Angels: Winged characters, they can fly but have very restricted choices of what they can attack. If they break their vows they lose their wings for awhile.
-Demons have wings AND spit fire but are super weak against holy type monsters and attacks.
-Toucher: Any monster ability can be turned into a player ability by bumping and stealing...there's a 7DRL there too.
-Ghost: I like the 7DRL Possession, where you possess monsters. Use strategy to jump from character to character.
-Charmer: Also there's the Bard or Preacher class where you charm baddies to fight for you, maybe you cannot fight for yourself or you lose some of your Preacher points or something. Or you can only charm certain types of baddies, like Snake Charmer or whatever works for your theme. You have a certain amount of charming points. In some thematic schemes this can be a Geisha or Mistress or some such. Succubus that may only charm male humanoids? Gigilobus that can only charm female humanoids? Bird singer, horse whisperer etc etc...
-Incubus: Must decided when to insert oneself into an unsuspecting creature and be reborn. So this character class could do no healing, and must save up energy by killing and eating souls in order to use the 'incubate' ability and be reborn out of another creature. The tougher the creature, the tougher the resulting incubus...you'd level this way, but the tougher the creature the more energy you'd need to incubate into it.
-Nuclear Man/Exploder: I had a 7DRL idea (I always am having new 7DRL ideas) where your character's power is to explode on command. He dies, but his spirit lives on and sort of reassembles itself. You are very weak as you are reassembling, and all your gear is gone, but you can kill ANYTHING in the area by exploding. The class would be 'Nuclear Man' in a campy scifi game, and you wouldn't explode so much as release a ton of energy. All gear and baddies are fried. Also in a sci fi setting you can over load a bit on radiation and then HAVE to explode or lose HP and die. The more radiation, the bigger the explosion. So the strategy is to wait and get more powerful, or blow up early when you find a good spot to recover.
-Mana Drainer (Egam, opposite of mage) - Like nuclear man, but fantasy themed. You slowly absorb energy from the area, getting hit with spells and such increases your energy bar by a ton. At some point you have to release all the power. Lose all gear, kill all baddies in the area that can be harmed, and end up weakened but with a depleted mana/energy bar.
-Boreworm: Can move through walls. Can't wield or wear anything, but heals and eats and grows like crazy.
-Gelly: Surely this type of race has been mentioned already. Eat stuff, take on some of that item's properties for a bit. Flesh and bone heal you, metal makes your stronger, magic stuff gives you more energy to make you faster and what not. Wood can give you splinters to shoot at enemies.
I'm sure I can think of more, but those are some cool ones.