Old MacDonald had a farm. He has appeared on Sesame Street many times over the years, beginning in the 1980s, and has been performed by Richard Hunt, Martin P. Robinson, Jerry Nelson, and Joey Mazzarino. He usually has a slight Scots accent, and appeared in two Sesame Street News Flash sketches in which Kermit the Frog investigates events on the farm.
Old MacDonald was also seen as the host of "Mac TV," where he introduced such barnyard music videos as "A New Way to Walk" by the Oinker Sisters. He has also occasionally been involved in street storylines, such as Episode 3750, where Shelly the Turtle wants to join his farm menagerie and be added to the song.
In most appearances since the 1990s, the old farmer has often been a Green Anything Muppet. However, he reverted back to his original Pumpkin form when he appeared in the Elmo's World episode "Farms."