"Ghost R Us" is the fourth episode of the Super Mario World animated series, aired in October 1991.
Mario, Luigi, Yoshi, and Princess Toadstool look for a cave kid named Oog Tar, while looking in an enchanted forest, everyone but Yoshi gets captured by a Magikoopa named Wizard Harmer, who hates it when people call him "Wizen Harmer"
Yoshi finds and saves Oog Tar from a Pirahna Plant, and the two team up to rescue Mario, Luigi, and The Princess, on the way, they encounter a Wiggler, which Yoshi eats, they find the warp pipe to the Ghost House where Wizard Harmer has the Mario Bros. Captured, Oog Tar also gets captured by him, now only Yoshi can save them.
Inside the Ghost House, Yoshi encounters many Boo Buddies, but he manages to defeat Wizard Harmer and rescue Mario, Luigi, Princess Toadstool, and Oog Tar, and they thank Yoshi.