I had a gnu once, got him from an exotic animal farm that was going out of business...he was pretty smart, but he was getting on in years. I had thought he & I could share our time together better if I could get him to learn little tasks like bringing in the newspaper, chasing away intruders and maybe even some stunts like rolling over, playing dead and walking on his hind legs......but it wasn't to be. He was either too stubborn or he knew it was beyond his abilities since he was not young enough....I guess you can't teach an old Gnu dog tricks.