Thanks, I’ve decided not to trap him though as I don’t want to risk him being euthanised by a shelter. The possum traps may also not be safe due to not being designed for cats and he in particular is quite large.

This guy is really friendly, he behaves like a pet. I could have been mistaken about the hissing, it could have been a hiss or it could have been a harsh exhale as he seems to huff and puff when excited.

For now the plan is to get some regular food down him and earn his trust to the point I can give some flea and worm treatment