The Witcher Bestiary - Ifrit
Ifrit Occurrence: Ifrits inhabit the Plane of Fire; mages who have achieved mastery in controlling the element of fire are able to summon them and force them into servitude.

Immunity: Immune to most effects, especially to incineration; ifrits come from another world, but they cannot be knocked down or stunned.

Susceptibility: Sensitive to silver and Specter Oil.

Tactics: Float in the air; use fire in combat.

Alchemy: Pyrite and ectoplasm.

An ifrit is a minor genie of fire, or, as some say, an elemental. It does not fulfill wishes, build palaces or make anyone rich, but it serves mages who research the element of fire if they can force the creature to be obedient. Ifrits can only be captured by a mage who intimately understands the nature of flames and has devoted himself completely to learning their secret. The creatures, with their connection to the element of fire, will judge their summoner and, if they find him worthy, will loyally serve him in all matters.