Glow-Fish

The glow-fish were a group of creatures that lived underneath the Thames River in the early 1800s. During their time in the Thames, they shared a symbiotic relationship with the Thames River Monster while chained at the bottom of the river. During the Thames periodic freezing, the glow-fish fed the river monster by melting the ice under anyone unfortunate enough to wander on the frozen surface alone. While their where abouts are unknown (much like that of the river monster), it is believed that the fish fled with the creature after it had been freed from the ownership of Lord Sutcliffe by The Doctor in 1814.

Appearences

 * Doctor Who (revived): Season 10 Episode 3 "Thin Ice"