Dennis gets into a fluffy mess when he runs into Von Screwtop's hadron collider with the professor's pet hamster, Galahad. To stop Dennis from completely changing into a hamster, the gang must sneak him into Wilbur's lab to use his reverse hadron collider and change him back!
Series 1: 38. Bertie's Backbone
Dennis and the gang train Bertie in the art of standing up to people so he can rebel against Walter's bossiness - but they train him too well and he becomes a dangerous reb ...
Series 1: 37. Grizzly's Great Outdoors
A snake bite causes Grizzly Griller to forget all his survival know-how, so it's down to his greatest fan Dennis to help him re-learn his survival skills and help them all ...