Scooby-Doo! and the Loch Ness Monster (2004) on Netflix

Plot summary

Mystery Inc. goes to Scotland so that Daphne can visit her cousin Shannon and everyone can attend the annual Highland Games at Blake Castle, her family's ancestral home. Shannon tells them the Loch Ness Monster has been frightening people at the castle. The gang also meets Del Chillman, an enthusiast and amateur cryptozoologist, and Professor Fiona Pembrooke, a scientist who has put her career on the line to prove the creature is real. Colin and Angus Haggart are brothers who compete in the games; their father is Lachlan. Sir Ian Locksley, who runs Scotland's natural history museum, is head judge of the games, Pembrooke's rival, and certain that the monster is not real. One night Shaggy and Scooby-Doo slip into the kitchen and end up running from the monster, which wrecks the playing field.