Chieftain

Z: Ancestral Fury

 * Cooldown: 120 seconds
 * Increases health by 100% and energy by 50%, but decreases attack range by 4 for 10 seconds. Dealing damage decreases the cooldown by 1 second.

Q: Ram

 * Cost: 15 Energy
 * Cooldown: 10 seconds
 * Description: Charge to the target enemy causing a 1 second stun to all enemies in a radius of 2.5, while knocking back and dealing 75 damage.
 * Note: Increases your movement speed by 5 and temporarily allows you to pass through units by sightly knocking them back. The energy cost is applied after hitting the enemy

W: Shockwave

 * Cost: 25 energy
 * Cooldown: 15 seconds
 * Description: Unleashes a shockwave that spreads forward to a radius of 5, knocking up enemies and dealing 110 damage.
 * Note: The area of effect indicator is currently bugged, the real area is smaller. The damage is applied after the knockup. 

E: Blood Frenzy

 * Cost: 50 energy
 * Cooldown: 60 seconds
 * Description: For 20 seconds, allied units within 5 range of Chieftain will recover 10hp per second.

R: Calldown: Cow

 * Cost: 40 energy
 * Cooldown: 15 seconds
 * Description: Calls down a cow that can't be controlled and will follow the chieftain. Cows have 300 health, 0 armor, 0.1 regen. Deals 11 damage with an attack speed of 1.5
 * Any upgrades and stats to the Chieftain Also apply
 * Maximum 1 cow

T: MCD

 * Cost -5 energy
 * No cooldown
 * Description: Deals 100 damage to the Chieftain or a Cow, increasing the attack and movement speed of all allies by 10 for 60 seconds. Stacks up to 5 times.
 * Note: The damage is reduced by armor and by "Debilitate" status. The damage is increased by Focus Fire and Battle Aura.

Strategy
Chieftain is able to tank massive waves of enemies with both his own body and cows, while providing some utility to the team.

Because of the nature of Ancestral Fury, HP max and Energy Max upgrades are highly recommended. Apart, armor upgrades are worth considering if you are focusing on cow perks. Don't be afraid to use Ancestral Fury to get enough energy to call down a cow.

If you are not planning to get the cow perks, you should buy Cooldown Reduction and some extra Energy regen to help you spam abilities in order to get ancestral fury.

Damage upgrades aren't recommended for this hero in bigger modes because of his low base numbers.His damage abilities aren't the best, but can help decimating groups of enemies in the early game. Most of the times, you should use these abilities to stun enemies and/or reduce the cooldown of Ancestral Fury.