I've killed and tortured thousands.... Of insects. HEH HEH HEH. Nah but really every now and then I'll take an injured moth or fly and drown it in a cup of water, and other similar fucked up things xP.
One that I feel bad about though, I was at a cousins house and I was like "GUYS WATCH THIS" and I stepped on a really big, but cute/innocent lizard. The entire party was pissed/offended at me stepping on it. :c