I worked on Black Ops 1 and 2 intermittently over the course of probably 2 years total.  Somewhere between MW3 and Ghosts I think?  It was a ton of fun and zombie concepting always brings out the best in me!  Anyway, the final products Treyarch delivered were both outstanding and it was a privilege to be a part of it!  My contribution to BLOPS 1 and 2 was almost entirely concept design.  Unfortunately, I cannot show my zombie concepts; however may show up in future titles.  Only time will tell. :)