The final instrumental piece and the final song on the "McCartney" solo Apple LP/CD is a tune/improv/drums experiment entitled "Kreen-Akrore". The song and title were inspired by a UK ATV television show on a tribe from the Brazilian jungle known for their defense of their territory - the Kreen-Akrore Indians. The show's title was "The Tribe That Hides From Man".
The song was recorded at Morgan Studios probably between February 18 and 20 1970 ( the television show aried on the evening of February 17). The song was recorded in two parts: the first part including drums and the addition of organ, piano, guitars, bass as well as their vocals being speeded up to imitate animal sounds as well as hitting the back of a guitar to create that stampede sound. The second part of the song was recorded with more drums and also the addition of vocals, organ and guitar, bass and Paul's heavy breathing. The stereo mix was probably completed around the same time as the completion of the recording on February 20 1970.
It's an interesting experiment but not the best instrumental of the LP. The song has never been performed live as far as I know and can only be found on the "McCartney" album.