A fool, referred to in the transcript as a clown, was a character in an early 17th century staging of William Shakespeare's play As You Like It. The Shakespeare Notebooks speculated that, as the clown's inclusion was a diversion from all other known sources of the text, he only appeared in a single performance and was "perhaps" an extreme example of improvisation by the actors involved.
The clown had been "a lord", possessing knowledge about "grave disruptions in the sky" and sharing "strange tales of wounds within the walls of time". Wearing a motley coat, he travelled through time and space with Perpugilliam Brown in the TARDIS, the "star-crossed ship of time" which acted as their home. He encountered Jaques in the Forest of Arden and asked him if he had seen "a press abandoned in the woods". He further explained that he "set up the HADS to move the girl upon this very plot" but "the course co-ordinates hath slipped and sent her to a place that [he knew] not", forcing him to "make pursuit". In another scene, the clown and Peri conversed with each other until the clown operated a device which "filter[ed] feedback on the sub-etheric band" and sent "a signal soaring through the spheres". This resulted in the TARDIS appearing off-stage with "a great wheezing and groaning" thus ending the scene as the clown and Peri departed.
The addition of the clown in the transcript of this performance merited its inclusion in the Shakespeare Notebooks because the character was clearly based upon the Sixth Doctor, with Peri an explicit fictionalisation of his companion of the same name. (PROSE: As You Like It)