Arachnosaur

The arachnosaur is an alien from the IDW portion of the Generation 1 continuity family.

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The arachnosaur is a large spider-like creature native to the planets LV-117 and LV-118. It dwells in the more arid regions of the planet, and buries itself in the sand in order to ambush its prey. Springing out of the sand, it is a fearsome sight, with its eight massive legs and giant fangs, but if it is met with resistance it will flee.

Fiction

IDW Generation 1 continuity

Wheelie was ambushed by an arachnosaur in the deserts of LV-117. The beast inadvertently bit into his energon convertor, shocking it with a jolt of energon. The arachnosaur fled without devouring Wheelie, but he was forced to make repairs to his convertor. Spotlight: Wheelie

An arachnosaur was skulking around in the shadows of LV-118 when Garnak and Codder pulled Rodimus back to their ship. Space Opera Part 1: The Stars My Destination