A very thorough blog explains all the mysteries I puzzle over.
Sparks in Electrical Jelly states that it is the Green Man as I thought it might be.
But I'm not sure about this description-
This model was more akin to the dim ogres found in Terry Gilliam film, however, grunting with slow, dim-witted befuddlement, chronic and everpresent indigestion suggested by moog sounds at their most flatulent.
I think he was dancing, part of a dance music reference throughout the soundtrack.
The Green Man cannot come soon enough. Apparently he lives near the Haldon hills and will visit Exeter in a month or so. But there could be more than one Green Man. If he chooses to dance then his style should be respected.
Last year there could have been a change in the mood of the music when the Green Man appeared. Is there scope for a remix?