Arachnid Magic

Arachnid Magic (蜘蛛の魔法, Kumo no Mahō) is a peculiar form of magic that's not widely-known. In fact, it was invented quite recently by its only known user — Arcadia Widow, a Dark Mage infamous throughout the world for her various evil deeds. It's considered to be a form of the Black Arts, as it utilizes various hexes in order to subdue its opponents. As the name states, it revolves around the theme of spiders, one of the world's most venomous creatures, thus being one of the few existing animal-themed magics. It's because of this that the magic also finds its basis in Poison Magic; this makes it count as a Subspecies Magic. Due to the way it's used under normal conditions, it's considered to be a Caster Magic.

Trivia

 * This magic is based off of a magic of a similar nature from the anime/manga series, Soul Eater.