I am the Aunt of Frankenstein . . . ?

There's a distant cousin that I have that I see only at really big family dinners when all of the extended family attends. My family is huge and I don't really know all of my relatives but you just smile, say "Hi Auntie/ Uncle, how are you?" and move on to the next person. There's one "cousin" that is very tall, thin, broad shouldered and has a square head. Between my immediate family's cousins we call him Frankenstein, because all he needs is a set of bolts on his neck and he could star in a B-rated horror film. We were talking about him at Christmas time and realized that none of us knew his name, we always referred to him as Frankenstein. Another wacky family thing is that because my great-grandfather was a bit of a manwhore and had 8 wives and countless mistresses, my grandfather and his youngest brother have a good 25-30 years between them in age. The children of his youngest brother are technically my aunts and uncle (despite their ages), and so my sister was asking my mom if we were "aunts" to anyone... And guess what - we are the aunts of Frankenstein. I still don't know his real name - but what a funny title that makes!!