This is pretty funny... from a new interview with Strikeforce's Shamar Bailey:

Q:  Can you ask Wilcox why he stole Seth Petruzelli’s nickname? I mean, is MMA really big enough for two “Silverbacks”? I’m really don’t think it is. Now, Seth told us he got his nickname because The Silverback actually has the smallest penis-to-body ratio in the animal kingodm. It’s true – he said that http://prommanow.com/index.php/2008/09/26/seth-petruzelli-return-of-the-silverback-pro-mma-exclusive-interview/. I just wonder why Wilcox calls himself “The Silverback”?

A:  (laughs) Wow! Ummmmm… that’s a very good question. Sounds like Wilcox should have researched his nickname as hard as Petruzelli did huh? Whatever works for him I guess.

Full interview with Shamar Bailey