The Roid Rage Psycho is a creature that was created by a vicious enemy named Sledge. (Continue)
Involvement
The Roid Rage Psycho is seen during the main story quest in Sledge's Safe House that requires you to collect Sledge's Mine Key. At the end on the inside of the building, it is a semi-large round room that the key is located. The creature will be located at the end of the room and start to attack you, along with lots of Midget Psychos. Defeat the Roid Rage Psycho in order to collect the Mine Key.
Strategy
This enemy attacks in 2 ways, the first being a traditional melee attack which causes large amount of damage. The second is a ranged attack in which a grenade with an Explosive MIRV mod is thrown. Alongside the Roid Rage Psycho, there are lots of Midget Psychos attacking you once you commence the battle. (Recommended to do this boss in Co-Op)It is possible to defeat this boss without getting damaged by his melee attack by going in the back of the round room (the way you came from) and go into a hole where there is a fence in front. This circumvents the melee attack's damage, but not the grenade attack. Bullets will NOT go through the fence, but if you have a weapon called TK Wave, the plasma shots will go through the fence and cause damage. There is also a small gap between the fence and the railing the fence is attached to, allowing you to get critical headshots with a sniper rifle from a place of relativesafety. You can get out of the hole at any time and come back in while attacking with other weapons. The Roid Rage Psycho has no shields, but a large amount of health. This and its size make the fight a little complicated.
Due to his large size, getting critical headshots is quite easy and makes the fight much easier. If you are taken down, the easiest way to get second wind is to kill one of the many midget psychcs, which can be easily done using a shotgun to the head as they will run up to you while downed.