"Earnest" or "The Secret File of the Manly Man" - S1.E7

Ernest Anyway's finally caught the Abominable Snowman, and now he's after the poor Loch Ness monster! When the Spy Dogs hear of this, Ralph is alerted immediately, and goes off to Scotland, where he meets up with fellow Spy Dog, Erin (*sigh*, as Ralph would say), and Erin then proceeds to tell him the true story behind the Loch Ness monster. As soon as she finishes though, Ernest is hot on their tail, and it's up to Ralph and Erin to save poor Nessie from Ernest.