Larva by CrazyFredy

Tiers 1-4 talents replace your trait and grant you a new form. After that, the talents will only grant upgrades.

Zergling
Passive: Movement Speed and maximum Health increased by 25%.
Passive: You now have a melee Basic Attack that deals medium damage with a fast Attack Speed.

Roach
Passive: While Burrowed, your Health regeneration is increased by 50% and you can move like normal.
Passive: You now have a ranged, high-damage Basic Attack.

Queen
Passive: You now have a ranged, low-damage Basic Attack.
Passive: Rapid Regeneration now affects all allied Heroes within 3 range of you, but you are no longer affected, and its regeneration effect is reduced to 25% of maximum Health.
Active: You can activate your trait to place down a Creep Tumor that spreads Creep, granting allied Heroes who walk on it 15% increased Movement Speed.

Swarmling
Passive: Amount of Zerglings increased to 3, can be controlled invidually [RTS-like controls.]
Passive: Respawn time decreased by 50% and death now only grants 0.25% of the normal XP to the enemy team.
Passive: Basic Attack damage and Health reduced by 33%.

[Can only choose this talent if you have chosen Zergling at the previous tier.]

Raptor
Passive: While attacking targets outside your Basic Attack range, you now leap at them, inflicting a Critical Hit.
Passive: You can now leap over small obstacles.
Passive: Basic Attack damage increased by 50%.

[Can only choose this talent if you have chosen Zergling at the previous tier.]

Corpser
Passive: Basic Attacks afflict enemies with Parasite for 4 seconds. If the afflicted enemy dies during that time, they spawn a low-Health Roachling that loses its Health over 4 seconds. Enemy Heroes spawn 3 Roachlings instead of 1.
[Can only choose this talent if you have chosen Roach at the previous tier.]

Vile
Passive: Basic Attacks now slow enemy Movement and Attack Speed by 5%. This stacks up to 5 times, equalling a maximum of 25% Movement and Attack Speed reduction. The slow is lost after not attacking the slowed enemy in 5 seconds.

[Can only choose this talent if you have chosen Roach at the previous tier.]

Swarm Queen
Passive: Rapid Regeneration cooldown is reduced by 1 for every allied Hero it affects, and it now heals instantly instead of over time.
Active: You can activate your trait to place down a Creep Tumor that spreads Creep, granting allied Heroes who walk on it 15% increased Movement Speed and you 30% increased Movement Speed.

[Can only choose this talent if you have chosen Queen at the previous tier.]

Brood Queen
Active: Infect an enemy Hero with a Parasite for 10 seconds. You gain vision of that Hero and their surroundings. While the Parasite is active, you gain a new set of Basic Abilities which you can only use once per Parasite. You can kill the Parasite by activating your trait again.

• [Q] Spawn Brood: If the infected Hero dies while the Parasite is active, 2 Broodlings will be spawned that attack enemies.
• [W] Blood Leech: Deal some damage to the infected Hero and heal for 50% of the dealt damage.
• [E] Ensnare: Slow the infected Hero's Movement Speed by 20%.

[Can only choose this talent if you have chosen Queen at the previous tier.]

Baneling
Passive: Respawn time removed.
Passive: Upon dying, you explode dealing high damage to all enemies within a small radius around you.
Active: Command selected Banelings to die. The death explosion has twice the range and damage this way.

[Can only choose this talent if you have chosen Swarmling at the previous tier.]

Locust
Passive: Respawn time removed.
Passive: You will die a minute after spawning from your Cocoon.
Passive: Your Basic Attacks now have 3 Range, and deal high amounts of damage over time.

[Can only choose this talent if you have chosen Swarmling at the previous tier.]

Hydralisk
Passive: Basic Attack damage increased by 100% and range increased by 1. [Attack animation still melee].

[Can only choose this talent if you have chosen Raptor at the previous tier.]

Mutalisk
Passive: You can now fly over all obstacles.
Passive: You can now also attack at range. [Melee Basic Attack animation is a swoop.]

[Can only choose this talent if you have chosen Raptor at the previous tier.]

Infestor
Passive: You can now use all of your Basic Abilities while Burrowed.
Active: You can activate your trait to turn all enemy minions afflicted by Parasite to your side. This ability has a 20 second cooldown.

[Can only choose this talent if you have chosen Corpser at the previous tier.]

Blightbringer
Passive: Your Basic Attacks now splash, affecting all hit enemies with Parasite. Additionally, they deal extra damage to enemies that have been hit by your Basic Attacks recently. Your Attack Speed is also decreased.

[Can only choose this talent if you have chosen Corpser at the previous tier.]

Lurker
Passive: Your Basic Attacks now splash, dealing more damage to secondary targets. You can now only use Basic Attacks while Burrowed.
Passive: You are no longer Invulnerable while Burrowed.

[Can only choose this talent if you have chosen Vile at the previous tier.]

Impaler
Passive: Your Basic Attacks now deal extra damage to enemy heroes equal to 2% of their maximum Health, and you can deal damage through Shields.

[Can only choose this talent if you have chosen Vile at the previous tier.]

[Swarm Queen evolution #1]
[Swarm Queen evolution #2]
(any ideas for what these could be are welcome)

Broodmother
Passive: Every 5 seconds, you summon a low-health Broodling that will attack enemies for minor damage. They follow you, and can be fully healed by your Rapid Regeneration.
Active: Infect an enemy Hero with a Parasite for 15 seconds. You gain vision of that Hero and their surroundings. While the Parasite is active, you gain a new set of Basic Abilities which you can only use once per Parasite. You can kill the Parasite by activating your trait again.

• [Q] Spawn Brood: If the infected Hero dies while the Parasite is active, 4 Broodlings will be spawned that attack enemies.
• [W] Blood Leech: Deal some damage to the infected Hero and heal for 100% of the dealt damage.
• [E] Ensnare: Slow the infected Hero's Movement Speed by 40%.

[Can only choose this talent if you have chosen Brood Queen at the previous tier.]

Broodlord
Passive: You can now fly over all obstacles.
Passive: Your Basic Attacks fire low-health Broodlings, which will continue to attack the target for 5 seconds after landing.
Passive: You are immune to melee Basic Attacks.

[Can only choose this talent if you have chosen Brood Queen at the previous tier.]

Swarm Host
You gain the Acid Pool Heroic ability.
Passive: You now have a large Health pool.
Passive: While Burrowed, you no longer have Stealth or Invulnerability, and you summon Banelings or Locusts based on your previous talent choice every 3 seconds.

[Can only choose this talent if you have chosen Baneling or Locust at the previous tier.]

Ultralisk
You gain the Frenzy Heroic ability.
Passive: You now have a large Health pool.
Passive: Your Basic Attacks now deal high damage and splash, but are quite slow.

[Can only choose this talent if you have chosen Hydralisk or Mutalisk at the previous tier.]

Choker
You gain the Abduct Heroic ability.
Passive: You now have a large Health Pool.
Passive: Your Basic Abilities double damage to lone targets.

[Can only choose this talent if you have chosen Infestor or Blightbringer at the previous tier.]

Ravager
You gain the Corrosive Bile Heroic ability.
Passive: You now have a medium-sized Health Pool.
Passive: While Burrowed, your Health regeneration is increased by 100% and you can move like normal.

[Can only choose this talent if you have chosen Lurker or Impaler at the previous tier.]

Ultimate evolution for Swarm Queen's evolutions
Ultimate evolution for Broodmother and Broodlord

• I've left out the precise numbers, balance is not my thing.
• Some of these evolutions aren't really lore-accurate: for example, in lore Hydralisks and Mutalisks can't evolve from Zerglings and aren't melee units. I based the Hydralisk on the unit in Starcraft: Ghost. It's not canon, but that was the only way I could fit the Hydralisk into this evolution tree without making the tree way too big.
• There are also a couple of evolutions I just couldn't figure out, so any ideas are welcome.
• If people show interest in this concept, I might do the remaining 3 talent tiers as well, but for now I've just done the first 4 as they are the most interesting.