@iridescent_slime seems it's called Hemicorporectomy. Not sure if we want a more speaking name or if this is good enough, also due to the fact that people looking for this kind of thing might search on google for it to find the name first. Maybe this pic can be tagged with that plus triple_amputee. It's a specific enough concept that a single post would be justified for it imo, otherwise we'll never find it again.
I've added bisected for now, but I won't object if anybody wants the technical term here as well. I can't foresee it being a very common tag in the long run, though.