Anything, and I mean anything, with more than four legs creeps me out totally. If I have to clean my own shrimp from the fish monger I have to do it several hours in advance of cooking them so the loathsomeness of pulling off their legs and heads is put behind me. When presented with a whole lobster I am completely at a loss as to how to eat it if I have to get the meat out myself. I love the meat but lose interest after wrestling with those hairy spiny legs and plates of shell. Bugs of every type horrify me.
Injections, on the other hand, do not bother me at all. As a youngster, whimpering at the doctor pulling out yet another needle, my mother took my chin in her hand and said sternly "You hurt your self at least twice this bad every day of the world. Now be quiet before I give you something to _really_ cry about. It worked.