There may have been plans for more palette swap Yoshis as DLC, but got cut for unknown reasons. It reuses artwork from GP1/2, Mario Kart Wii, and Mario Kart 7.Present in flash/datajp/commontex/tex/charap00.pac, in the first release, are character select icons for Yellow Yoshi and Blue Yoshi. They may have been used to test the camera.flash/datajp/select00/select00tex.pac has placholder sprites for the class selection and other sorts. There's also smaller versions of the same icons.flash/datajp/testdata/testdatatex.pac contains two Mario icons (much like the ones in test.pac), and sprites for a test menu and two images of old cars in Japan, most likely at some kind of car show.
In the final, he uses his appearance from Pac-Man and the Ghostly Adventures. The most notable difference is Pac-Man, as he uses his older model from GP1/2. Present in flash/datajp/commontex/tex/test.pac are test character icons of all the characters from the first release (Rosalina is there as well because her files are present in the first release) in dds format.