When was the last time Frank Oz performed Cookie Monster (or Bert)? I know he last performed Grover in season 40, but it seems like its been forever since Oz performed Cookie Monster.UGH. I am sick and tired of Frank being the end all be all of the character. David is doing just fine, and has been for years. David IS Cookie as far as I'm concerned. If Frank wants to come back and do a couple skits on Sesame Street in between whatever he's doing, that's great. But David and Eric have been doing solid. Heck, I don't even notice anymore. Eric has absorbed Grover flawlessly.