Loch Ness Monster

The Loch Ness Monster (or Nessie) is a plesiosaur (really a family of plesiosaurs) living in Loch Ness in Scotland, Europe on Earth (TOS novel Deep Domain).

Roberta Lincoln mentioned the creature(s) in the 1980s (TOS novel The Eugenics Wars, The Rise and Fall of Khan Noonien Singh, Volume 1. James T. Kirk mentioned it in 2269 (TAS novelisation Bem).  In the early 2270s, Montgomery Scott's one-time lover, Andrea Manning created a psychological manifestation of the creature to attack Spock with (TOS comic ...Like a Woman Scorned!).