Fenris Brood (ZERGLING SWARM) by KonofAiur

Fenris is a swarm of 6 zerglings.  At the core, Fenris builds up Larva slowly, up to a maximum of 6.  When a Zergling dies, as soon as a Larva is available, a new Zergling will grow in an egg for 1s per level and then burst out and will run (uncontrollably) to join the swarm.  

Fenris Brood has a basic 50% resistance to crowd control.

The zerglings are 20% faster than a regular hero.  Zerglings cannot move through other heroes, but can be pushed aside.

Fenris Brood has no mana limitations.

The pack jumps to target location, dealing damage in the area and gaining a 20% shield for every enemy hero hit.

Zerglings scatter, allowing all of them to attack individually.  Reactivate to boost attack speed by 50%, but lose Fenris Brood is now very vulnerable to AOE attacks until it Reconstitutes.

Zergling converge into ranks, unifying their health pool but preventing them from breaking formation to attack targets.  Reactivate to heal the pack rapidly on a stationary channel.

Passive Heroic: Zerglings become much faster, moving at 60% hero speed at all times.

Talent:
Swarmling Mutation: You now always have 6 larva ready.

Activate to transform all surviving Zerglings to Banelings.  Banelings move at reduced speed (normal hero speed) but explode for enormous damage if killed near an enemy hero.  Activating this ability spawns larva up to your maximum.

Talent: 
Centrifugal Hooks: The Banelings move 20% faster (normal Zergling speed) and deal more damage.

Activate to burrow after a 2s channel.  While burrowed, you are immobile but have stealth.  Using any abilty will cause Fenris to unburrow and gain 100% bonus damage on the first attack.