Much as I predicted in an earlier post, Dehaka from Starcraft will be coming to Heroes of the Storm. I don't know if he'll come before or after Tracer, but given that he's only just been announced, I'd guess he's next up after her.
Dehaka is one of the Primal Zerg - an example of the species as it existed before the evil Xel'naga Amon got involved in altering their genetics. Unlike the vast goopy swarm, the Primal Zerg were individuals who, through predation, could absorb some of the genetic material of their prey, taking on beneficial traits. In Heart of the Swarm, Dehaka acts as something of a guide to Kerrigan when she goes to the Zerg homeworld, and while he reserves the right to try to challenge her and devour her essence, he acts as an ally for now.
Dehaka's skills appear to be the following:
Z: Brushtalker: Instead of a mount, you can burrow to any bush or vent on the battleground every 40 seconds, which should make Dehaka pretty good at rescuing allies in need.
D: Dehaka's trait is Essence Collection. You get 10 Essence per Hero takedown and 2 per enemy minion killed nearby, to a maximum of 50. You can then activate the trait to regenerate health over the next 5 seconds for every stack consumed (not sure if this means it will last super-long at full stacks or, more likely, it will be more potent for each stack.) This can be cast while using Drag or Burrow (see below.)
Q: Drag: You lash out with your tongue, dealing light damage to the first enemy hit and dragging them with you for 1.75 seconds. Depending on the range, this might be a powerful tool to force enemies into a bad position.
W: Dark Swarm: For three seconds, you can move through units and you deal area damage around yourself, doing double against Heroes. This can be cast during Drag and Burrow.
E: Burrow: Burrow into the ground, entering stasis and becoming invulnerable for 2 seconds.
R: Isolation: Launch a biomass that deals damage, silences, and slows the first enemy hero it hits by 30% for 3 seconds. For 6 seconds, that hero loses sight of allied heroes and has greatly reduced vision.
R: Adaptation: After a 5 second delay, heal back 60% of the damage you took during that period.
So overall, it looks like Dehaka might not have a ton of damage output, but as a warrior, he's got some nasty crowd control and some nice survivability. I wonder what the cooldown on the trait and Burrow will be, because I could imagine if they're short enough, he could function a little like a Zerg Roach - messing things up and then dropping away briefly only to pop back up fully healed.
The initial alternate skin for Dehaka looks like it's in line with the Mecha-Tassadar and Cyber-arak as a kind of mech-version of the character. Maybe we need more Kaiju for them to fight?