Gate (wizard)

When a wizard casts Gate, he summons forth one of the greatest of all baatezu, the pit fiend.

In-game description
"Gate By means of this spell, the caster calls an outer-planar creature––the pit fiend––to attack his foes as well as himself, if he's not careful. The caster must use a Protection From Evil spell on himself (and comrades) to, keep the devil from noticing him. If the caster fails to protect himself in this manner, the pit fiend will tear the caster and his companions apart piece by piece, then feast on the remains."

Baldur's Gate II: Shadows of Amn

 * House of the Moon - Suldanessellar

Baldur's Gate II: Throne of Bhaal

 * Arcana Archives