Featured as a clip in Pastichio Medley (~5:26-5:48). Also appears in full on Billy's Gravity Demos and the 2012 MCIS reissue.
The version on Billy's Gravity Demos is much longer and faster, and alternates between fast & slow sections. The "Fuzz Version" on the MCIS reissue is shorter, a bit slower overall, and more distorted, includes a lead "solo" throughout most of the track, and does not include the slower section. Pastichio Medley uses the "Fuzz Version" for its clip, although it is heavily compressed and distorted, so the lead track is less distinguishable.