Danko the Dolphin is obviously not real. The trailer for this hero has confused the whole Dota 2 community. There are a lot of weird heroes in Dota 2 but we cannot expect Valve to name a hero ‘Danko’. Regardless of this fact, he has made the community question its authenticity. What a legend!
Danko is a Dolphin and his spells represent him as a carry. Most of his skills are damage dealing. The hero has three simple spells and an ultimate to cast. His list of spells includes Dank Dive, Puffer Punt, Echo Location, and So Long And Thanks for All the Fish. Further detail about each of his abilities is as follows.
Dank Dive allows Danko to dive under the water. When the hero is near any water substance, he can dive under the surface. The dive makes him invisible and he gains increased movement speed over time. When the hero reaches the water’s edge, he jumps and flies through the air. As he lands on the surface, Danko stuns the enemies in an AOE and deals damage. If Danko comes out on a water surface, he further gains movement speed until he hits the land.
Puffer Punt allows Danko to chew the flesh of a pufferfish. The meal inebriates him. As he eats the fish, his damaged resistance increases to all kinds of damage. The spell also creates a trail of water. After a short charge time, Danko throws the chewed pufferfish in a specific direction. If this fish hits enemies, it will explode and slow down the movement speed of all enemies in an AOE. Danko also creates a trail of water in the direction of thrown fish.
Echo Location lets Danko use a hypersonic wave. He releases this wave on the whole map which then bounces back when it collides with an enemy or an ally. The sound wave comes back at different times. The closer the enemy, the faster the wave bounces back. The wave then reveals the location of the enemy on the map. The faraway enemies are revealed slower than the closer ones.
So Long, And Thanks for All the Fish
His ultimate allows him to summon his pod to help. The pod joins him at his location for a short channel time. The summoned pod revolves around him and then jumps into the nearest water source. During the channel, if Danko or any pod member contacts an enemy, they will carry the enemy on their backs. The pod can jump from one water source to another to move forward but cannot jump back to the previous location. Enemies take the ride until Danko hits the land. During this channel time, Danko and other pod members can be stunned.
His hero-reveal trailer has made a lot of Dota 2 fans question Valve about its existence. However, we can easily say that no hero with the name Danko will arrive in Dota 2.