A slippy eel adjective
is used to describe someone on the highest level of lurking, able to 'slip' in and out without even being noticed gives them the ability to creep up on you and slip dog the hell out of you. Known for their monotonous voices, pot-bellies and dopey characteristics.
Connor: 'Quick Redders, slip dog's about!'
Redders: 'Ah cheers man'
Neil: (Monotone voice) 'I'm gonna have to dock you for internet use Aaron'
*Neil slips out the room*
Connor: 'His one Slippy Eel