Nessie

Nessie is a mosasaur kaiju created by TriStar.

History
Nessie and her species lived in peace, until her baby was kidnapped by a scientist who intended to sell the one-of-a-kind newborn; regardless of the fury of Nessie been invoked. H.E.A.T. were visiting Scotland, and investigated after seeing a video of what appeared to be Nessie attacking the scientist's facility. Godzilla appeared during one of Nessie's attacks and the two battled both on land and underwater in several fights.

It wasn't until later that Godzilla discovered Nessie was only attacking in order to find and save her baby - due to Randy broadcasting the baby's cries out over the Loch, which the mother reacted to. Godzilla then would team up with Nessie and - after getting her baby back from the scientist - help her rescue her infant by tearing open the cage the baby was locked in. Reunited with her baby, Nessie headed off, with her and Godzilla giving each other a 'parting roar'.

Trivia

 * Nessie is one of the only friendly monsters, other than Godzilla, to be encountered by H.E.A.T.
 * The Nessie creatures are likely to be a reference to the Toho kaiju, Manda, as the two have long, serpentine bodies and have aquatic habits.
 * Nessie is referred to as a "mosasaur" in her debut episode. This is, however completely inaccurate, as Nessie resembles a classic sea serpent more rather than any known species of Mosasaur found in the fossil record.
 * Related to the above information, the Nessie shown in the episode resembles the cryptid known as Cadborosaurus. Actual Nessie sightings claim it looks more like a classic Plesiosaur.
 * Nessie is also one of the two kaiju from Godzilla: The Series based off cryptids, the other one being the Yeti. The only difference is that the yeti turned out to be a machine, while Nessie turned out to be real.
 * Nessie is one of the only kaiju in Godzilla: The Series that is not a mutation.