Are your two leghorns roosters or hens ? Though he would probably stand up to them either way. He would probably make some large babies. But getting to the meat would be a pain if they were all featured like him.
I agree....that is an amazingly gorgeous roo, even looking a bit molty (is molty a word?). Colorwise - he looks like a black sex link roo instead of a barred roo...but I can't think offhand of any mixes that would make a BSL that look like him (genetics peeps wanna chime in here?) I would love to know because I would LOVE one like him. I also agree - looks almost like a Brahma/Cochin mix.
Oletymer, why don't you try posting his picture in the Cochin and Brahma breed threads, I am sure you will get a reaction out of them. And maybe someone their has seen a rooster at least as fluffy as he is.
PS If you do end up keeping and naming him a wizard's name would fit him to a tee.