These comical green skinned scaly henchmen are Boss Cass' foot soldiers. They are always willing to do whatever Boss Cass commands, no matter how ridiculous, or dangerous, it is. Boss Cass is usually cruel and arrogant towards them. Fairly harmless by themselves, but they are formidable foes when in larger numbers. They are the first minion enemies of the series.
They can be found in a number of guises, such as scuba gear in the Barrier Reef, on bikes terrorizing the roads of Southern Rivers, disguised as worker koalas and even as fire throwing pyros.
They are the most common enemies in Ty 1 and Ty 2. They're also the weakest enemies. Their standard attack is to get in close and give Ty a painful sock, though Ty can dispatch them with his boomerangs before they get too close. They die in one hit, though they are capable of avoiding bite attacks. In Ty 2 they can preform elaborate jumps to get behind Ty or attatch to his Bunyip mechs. Also in Ty 2 there are frills on motorcycles driving on the roads and spy frills which are disguised as koala workers which you can only see with the Infrarang or the X-rang. In Ty 1 and 2 Ranger Ken seems to dislike them greatly. In Ty 2, Ty meets up with a friendly frill and friendly large green lizard working as mechanics and food sellers named Keith and Sneath (frill.) They basically teach you what you've learned in Ty 1 in case you didn't play it. Ironically with Sneath not liking Boss Cass in Ty 3, Keith and Sneath end up working at a shop in Cassopolis.
By the time of Ty 3, it looks like most of the Frills have died out, with many emerging from graves in the ground as Quinkan-reanimated Zombie Frills. There are still civilian Frills in Cassopolis, however, so it is possible Cass still has a sizable population to command in the future. In Ty 2 and 3 a frill appears in the cart race tracks and in Ty 3's mini-game cart racing you can actually play as many characters including a frill.