Brutal Green Dragons are a stronger version of the Green Dragon. They do not require a specific slayer level to kill them. But, they can be killed as an alternative to Green Dragons if assigned them as a slayer task. Unlike other brutal dragons they are not found in the Catacombs, instead they are located in the Ancient Cavern. They also do not drop the draconic visage.
Locations
The Brutal Green Dragon can be found in the Ancient Cavern. The Ancient Cavern is entered through a whirlpool entrance east of Otto Godblessed’s house.