Collision mesh


Could someone help me out, as I’m at a loss? I can’t seem to figure out how to alter the collision mesh. I’m creating a custom Dragon, a bit smaller and with some personal tweaks. However, I can’t seem to get it fix that whenever I hover over a larger creature (e.g. Giganotosaurus), I’m stuck on it’s head and I can’t seem to get loose, whereby there is no visual collision present. What do I need to alter or change in order to make the skeleton, or the mesh more fixated with the right proportions?

Any help would be appreciated!

Kind regards,