From the Super Mario Wiki
It is revealed in the episode that Cheepy's mother had lost him and was frantically searching for him, even employing the Missing Bird Bureau to aid her. Eventually, Cheepy's mother, being extremely near-sighted, mistakes Toad for Cheepy.
Mario, Luigi and Princess Toadstool discover that the real Cheepy is found to be frozen in a block of ice. Freeing the Birdo using his fireballs, (Super) Mario, Luigi and Princess Toadstool surmize that he is the missing Birdo. Eventually Toad is dropped from the sky during a botched flying lesson from Cheepy's mother, landing in the campsite of Mario, Luigi, Princess Toadstool and Cheepy, who Toad then returns to his mother.
Later on, after King Koopa and his followers are defeated, Cheepy and his mother invite Mario, Luigi, Princess Toadstool and Toad to their home for lunch; though this lunch turns out to be large, talking worms.