Zelas Gort

Zelas Gort (Japanese: 水母召ゼラス・ゴート, Kanji translation: Water Mother (Jellyfish) Summon/Call, Romanji: zerasu gōto) is a water shamanistic magic summoning spell. Because of its name, there has been some controversy about whether it is a black magic spell that draws power from Greater Beast Zelas Metallium instead, but all credible sources including the Encyclopedia Slayers and Slayers Reading list it as a shamanistic spell. Further proof can be found in its kanji representation: while Zelas Brid is written with the kanji meaning "beast" and "king" in its original written form, Zelas Gort is written with the kanji meaning "water", "mother" (together meaning "jellyfish") and "summon" instead. This spells summons a huge jellyfish, which doesn't seem to be bothered by the lack of water. It seems that the caster has an amount of control over the creature and can use it to immobilize foes.

This spell was only cast by Naga the Serpent in the novels, but Lina Inverse also uses it in Slayers Next, hinting that she learned the spell from her former companion.