The pattern we chose was simplicity 2853 and it was lovely, not too fiddly and really comfy to wear when completed (yes, I tried it on...). The only adaptation I made was attaching the head to the body as a 'hood' so she did not have the fuss of two separate pieces. It had elasticated leg and sleeve cuffs which ensured the slouchy fit was manageable.
The only annoying thing about this project was the fabric we chose. It was incredibly soft thus why we chose it but my god could it fray! It went literally everywhere to the extent that I had to hoover twice and so I made the call to use my overlocker for this project, which was fine once the mess had been cleared up.
The reason Jade, a twenty year old woman wanted a bear suit it her complete and undying love/obsession with bears (she went to feed some at the zoo a few weeks ago). Her favourite type are these black bears. I think they are American.