I actually very much doubt that a xeno has a lot of weight to it; drones walk on walls and ceilings with ease, and the weight of the queen being pulled out of an airlock didn't tear Ripley's foot off. Also consider that during the first movie, the Xeno was supposed to be able to squeeze into smaller spaces than its body size, (so less of a solid structure) and despite seeing a xeno skull in Predator 2, seeing one ran over by an APC it didn't look very solid at all. I think it's a very strong creature, but not necessarily heavy. (Eg; When I'm in the lab, I can pick up a crab with ease as a lightweight animal, but if it latches into something with its claw, can I hell pry it open). 😂