The XP-36 landspeeder was a repulsorlift vehicle, similar to a series of landspeeder designs produced by SoroSuub. It was a lightly armed, high performance speeder.
Prototype from Kenner's presentation binder
The XP-36 is only known to have existed as an unproduced toy prototype that was designed for the Kenner toy line in the mid-1980s. The name was obviously intended as a reference to the XP-38 mentioned in Star Wars: Episode IV A New Hope, and, was intended to be part of The Epic Continues toy line.