Dehaka has been properly revealed.

Warrior, classified as Easy.

Can't use a mount. Instead his Z allows him to teleport to any bush/vent/maphidingspotthingy.

Trait: Essence Colector: gains 10 essence on hero kills and 2 on minion kills, storing up to 50. Can be activated to consume the stacks for a heal over 5 seconds, total depending on how much essence was consumed. Talents also cause this to give other bonuses.

Q: Drag - Tongue skillshot, light damage, first enemy hit will then be moved along with you for a while.

W: Dark Swarm - Negates unit collision and deals damage around Dehaka, doubled against heroes. One talent causes this to also work as spell shield.

E: Burrow - Baseline ice block. Can still activate his trait during this.

R1: Isolation - Single target skillshot. Damages, slows and silences for 3 seconds. Also causes the target to not have allied vision and lowered vision radius for 6 seconds.

R2: Adaptation - Activate, initiate 5 second countdown, recover 60% of all damage suffered during the 5 seconds.

Also amusingly, some pictures show him without his arm and some show him with it. So it seens that he can regrow it over the course of the game.