Toxic Terror originated from a catastrophic chemical spill in the laboratory's waste containment unit, where volatile compounds fused with organic matter to create a sentient embodiment of fear. It emerged as a failed experiment designed to study fear responses, but the contamination mutated it into an autonomous entity that thrives on spreading terror throughout the course.

Toxic Terror possesses a semi-corporeal form that allows it to phase through contaminated surfaces, leaving trails of corrosive slime. It emits a low-frequency hum that induces anxiety and disorientation, and its touch can cause temporary paralysis through neurotoxic exposure. The entity regenerates from toxic pools and grows more potent with increased contamination levels, making it nearly impervious to physical attacks.

Toxic Terror haunts high-contamination zones on the course, causing players to avoid areas or make rushed decisions out of fear, thereby amplifying the psychological decay and challenges of navigating the deteriorating laboratory environment.