Boss Battle Specialist

Boss Battle Specialist is an Achievements (PvZ: GW2) that was introduced in the Trials of Gnomus DLC. To earn it, the player has to enter the Mystery Portal inside the Town Hall and defeat a boss in Boss Hunt on Hard difficulty.

Trivia
* It is comparable to the Garden Hardcore Achievements (PvZ: GW) in Plants vs. Zombies: Garden Warfare, as both need the player to complete a mode on Hard difficulty.