needs to be tamed - the 'crabbing' (sic) is it growling which lets you know of it's displeasure - this is not some personality thing like a crabby human. When animals growl they are unstable - meaning they'll probably bite if pushed, and you need to 'push it'. Get yourself a pair of thick fleece gloves, put them in it's nest/bedding a couple of nights first, then use them to handle it. You must dominate the animal - let it know you are the 'pack leader' - animal psychology 101! Hold onto it and pet it / give it snacks with the gloves on - it'll think you are a fellow glider (from scent) and will be more accepting than your bare hand. Just needs to be handled more... it will become tame over time like the other glider. Probably never handled as a youngling. You must get it out of this feral state, which is stressful.