Summoner

The summoner is a new form of the arch-vile in Doom (2016).

Unlike the attacks the Arch-vile has in Doom_3, the summoner doesnt only summon a set amount or small assortment of demons and will continue to summon demons rapidly until dealt with. It'll teleport around the area it appears in using projectile attacks that deal medium to large amounts of damage to whatever it hits and summon every kind of standard enemy that has appeared at that point in the game. Unless you prefer the company of several Hell Knights it should be killed without hesitation. If there's a berserk powerup or if you have enough chainsaw fuel it should be priority.

Pre-release
The summoner was known as the arch-vile in pre-release versions of the game, with all of its codex entries referring to it as such. This was changed very close to the game's release.