Is it even possible to add at this point? Anything that has a reputation as "easy" is sure to be full, if it is even possible to add.

To answer your question, I found physical anthropology (anthro-140) to be pretty interesting and not too hard. I took it in the summer and got an A. Anthro-115 was also cool, but a harder overall class because you get deeper into the anatomy aspects. I would also HIGHLY recommend Biosc-126 (ecology and field biology) with Ray Goralka, but it isn't offered this semester unfortunately. It may have changed since I took it but it was a blast because you actually go out to parks and nature areas to observe wildlife and plants, so it's pretty refreshing compared to most classes. Not possible during covid I guess.

As far as doing something not too taxing, you can't really go wrong with Biosc-101 if you cant find anything else. Pretty dry but it is an introductory course after all, and probably meant specifically to fulfill this requirement for those who aren't sure what else to take.

Of course, YMMV because I didn't take these classes with most of the current teachers or fully online.

tldr; anthro-140, Biosc-126, Biosc-101