Dr. Sheldon

Dr. Sheldon, most often simply called Sheldon, is an elderly man who is known to be a mysterious, powerful witch doctor.

In The Super Mario Bros. Super Show! episode "Jungle Fever", Mario, Luigi, Princess Toadstool and Toad venture to the Amazon Jungle in search of Sheldon, who they believe can help them defeat the evil King Koopa.

Unfortunately, before Mario, Luigi, Toad and Princess Toadstool, who are distracted by King Koopa and the Koopa Pack, can reach Sheldon's village, King Koopa and his Shyguy minions reach it first. As Sheldon is in the process of checking several Mushroom Person patients with his assistant, Butterfingers, King Koopa has his Shyguy's grab Sheldon, puts him in a sack and run to King Koopa's base-of-operations in the Amazon Jungle.

Brought to King Koopa's camp atop a large, stone structure, Sheldon is forced by King Koopa to create him a potion that can turn Princess Toadstool to stone, under the threat of being fed to two starving Piranha Plants. Released from his sack prison, Sheldon, grabbing some supplies, begins work on a potion.

After several long moments of watching Sheldon create a potion, King Koopa, becoming impatient with Sheldon, begins to accuse him of stalling the creation of his potion for time. Disagreeing with King Koopa, Sheldon reveals his potion is ready, just as Princess Toadstool and Butterfingers arrive, having found King Koopa's base due to the fumes emanating from Sheldon's potion.

Having his Shyguy minions restrain Princess Toadstool, King Koopa proceeds to order Sheldon to douse her with his potion. Cheerfully obeying King Koopa, Sheldon, ignoring Butterfingers protestations and accusations of him being a traitor, throws a bucket full of his potion at Princess Toadstool, though not before telling her to duck.

Doing as Sheldon instructs, Princess Toadstool, as well as Butterfingers and King Koopa's Shyguy henchmen, watch in shock as the potion, having missed Princess Toadstool, douses King Koopa; Being hit with Sheldon's potion, King Koopa proceeds to fall to the ground, scratching himself crazily, screaming of being unbearably itchy.

As King Koopa writhes and spasms on the ground, Princess Toadstool and Butterfingers realize that Sheldon has not joined King Koopa and is conspiring against him the entire time he is captured. With King Koopa defeated, Princess Toadstool asks Sheldon if he can cure Mario, Luigi and Toad, who are unbelievably itchy, due to being covered in King Koopa's Koopa Strength Itching Powder; hearing this, Sheldon agrees to help Princess Toadstool in curing Mario, Luigi and Toad.

Later, Sheldon, Butterfingers and Princess Toadstool having returned to Sheldon's village, unveil the cure to King Koopa's Koopa Strength Itching Powder to Mario, Luigi and Toad, spaghetti. As Mario, Luigi and Toad ate this spaghetti antidote, Sheldon is asked by Princess Toadstool if the spaghetti will cure Mario, Luigi and Toad's itches; Sheldon replies to Princess Toadstool's question by saying that the spaghetti will not cure Mario, Luigi or Toad's itches, but it will distract them to the point that they will not notice their itches.