Interfacer is a seraph shotgun in Borderlands 2 manufactured by Hyperion. It can only be obtained as a rare drop from Voracidous the Invincible, Dexiduous the Invincible or Omnd-Omnd-Ohk in Ultimate Vault Hunter mode, or from the Seraph Vendor in Hunter's Grotto in True Vault Hunter and normal modes.

How do you get the butcher in Borderlands 2?

The Butcher can be obtained randomly from any suitable loot source, but has a higher chance to drop from Uranus, 010011110100110101000111010101110101010001001000, and legendary loot midgets.

Where is the Seraph vendor in Hunter's Grotto?

Seraph vendors are found in the town of Oasis, the Badass Crater of Badassitude, inside the Aegrus Sophisticates' Lodge in Hunter's Grotto and in Flamerock Refuge.