Back in the early 90s they released a set of videos called The Comic Book Greats that was hosted by Stan Lee. This was around the time Image was starting up and it involved most of the big guys of the time...Todd McFarlane, Rob Liefeld, Jim Lee, Whilce Portacio, and so on.
Todd and Rob seemed to be in the most of them, with each doing a solo video, a team video on Overkill, and then they led the "How to Create a Comic Book" where they pulled in Jim and Whilce to go over some of the concepts of comic creation.
This piece is one of the coolest things I remember from the videos - a huge piece that Jim pencilled and then everyone else hopped in to ink. Mostly it was Whilce doing the inking but Todd and Rob hopped on and helped with some of it, making it one of the rare jam pieces all 4 artists touched the same character on.