Fog Worm

A Fog Worm appears in Series 5.

In Primeval
In Episode 5.5, when an anomaly to the Precambrian opens in a classroom during the convergence, the fog pours out and a lone fog worm slithers around the classroom. Abby and Becker are sent to capture the worm, but find it difficult due to the fog. It is presumably either killed or captured by Becker.