Some weird holocaust experiments?

I want to know if anyone knows any 'different' medical experiments by Nazi's in WWI I know one where they cut someone open and put a live cat inside them and sewed them back up to see how long it took for the cat to get out. I am interested in this because I'm doing a paper for my History cl and need some weird methods used by them. Just generally cruel and unthinkable punishment. Like how they used to inject things into twins' eyes... thanks you'll be a huge help!