Koopa Strength Itching Powder
Koopa Strength Itching Powder is a white powder which induces itchiness in whomever it covers; Koopa Strength Itching Powder only appeared in The Super Mario Bros. Super Show! episode "Jungle Fever".
Due to it's name, it can be surmised that Koopa Strength Itching Powder was an invention of King Koopa and his Koopa Pack, to be used in battles. Koopa Strength Itching Powder can apparently be placed inside Bob-ombs, which can, in turn, be carried by Albatosses and dropped on targets.
Once someone is doused in Koopa Strength Itching Powder, they steadily become more and more itchy, to the point that the itching becomes almost unbearable. No known cure for Koopa Strength Itching Powder was ever revealed, leaving how Mario, Luigi and Toad were cured of it unknown.