Arnold Deensfrei is a minor character in Seinfeld. He is played by Robert Katims.
Arnold first appears in "The Jimmy" as an executive if AMCA (short for Able Mentally Challenged Adults). He thought Kramer was mentally challenged when he met him in a taxi cab.
He appeared in "The Finale, Part 2" attending the trail in Latham County. A deleted scene had him mentioning about how Kramer pretended to be mentally challenged. Kramer stated that it was the novacane that made him do that as Judge Arthur Vandelay tells Kramer to be quiet.