You can choose up to 12 heroes by clicking on them or through the "Find Hero" field.

Strength
Alchemist
Axe
Bristleback
Centaur Warrunner
Chaos Knight
Dawnbreaker
Doom
Dragon Knight
Earth Spirit
Earthshaker
Elder Titan
Huskar
Kunkka
Legion Commander
Lifestealer
Mars
Night Stalker
Ogre Magi
Omniknight
Primal Beast
Pudge
Slardar
Spirit Breaker
Sven
Tidehunter
Tiny
Treant Protector
Tusk
Underlord
Undying
Wraith King
Agility
Anti-Mage
Arc Warden
Bloodseeker
Bounty Hunter
Clinkz
Drow Ranger
Ember Spirit
Faceless Void
Gyrocopter
Hoodwink
Juggernaut
Luna
Medusa
Meepo
Monkey King
Morphling
Naga Siren
Phantom Assassin
Phantom Lancer
Razor
Riki
Shadow Fiend
Slark
Sniper
Spectre
Templar Assassin
Terrorblade
Troll Warlord
Ursa
Viper
Weaver
Intelligence
Ancient Apparition
Crystal Maiden
Death Prophet
Disruptor
Enchantress
Grimstroke
Invoker
Jakiro
Keeper of the Light
Leshrac
Lich
Lina
Lion
Muerta
Nature's Prophet
Necrophos
Oracle
Outworld Destroyer
Puck
Pugna
Queen of Pain
Rubick
Shadow Demon
Shadow Shaman
Silencer
Skywrath Mage
Storm Spirit
Tinker
Warlock
Witch Doctor
Zeus
Universal
Abaddon
Bane
Batrider
Beastmaster
Brewmaster
Broodmother
Chen
Clockwerk
Dark Seer
Dark Willow
Dazzle
Enigma
Io
Lone Druid
Lycan
Magnus
Marci
Mirana
Nyx Assassin
Pangolier
Phoenix
Sand King
Snapfire
Techies
Timbersaw
Vengeful Spirit
Venomancer
Visage
Void Spirit
Windranger
Winter Wyvern