|Age||Born in the Year of the Significant Triangle in the Century of the Three Lice 1855 UC (130 in Reaper Man)|
|Physical appearance||Aged and feeble|
|Books||Moving Pictures, Reaper Man|
When we first meet Windle he is a wheelchair-bound old wizard who does not hear much and doesn't do much. He is the oldest wizard in the world - having presumably held that distinction since the death of Greyhald Spold, his contemporary as a student (whom he mentions in a few reminiscences of his youth). Unlike Spold, there is no evidence of him playing any part in University politics or heading any of the 7+1 orders of wizardry, which probably explains his long lifespan. His wheelchair is used in the battle against the creatures from Holy Wood.
In Reaper Man, he is supposed to die, but as Death is ...not available, he instead turns into a Zombie and joins the Fresh Start Club. During his time as a zombie, he loses bodily functions, and is forced to make his heart beat, his lungs breathe and his muscles move all using his head.
Freed from the blur that normal living puts on the mind, and from the further encroachments of old age, Windle begins to see the world in a completely new way. He meets people he had no idea existed, and wouldn’t ever have listened to before. He worries away at the “inexplicable phenomena” which are consequences of Death being on leave, a general excess of life force. He realises that among these there is a predator which threatens the city and leads the Fresh Start Club in the resistance to it, rescues the wizards who have been overcome by it, and generally saves the day. Not being at heart a career zombie, having paved the way for the happiness of a trans-species couple, he lurches off to the bridge where he had tried to do away with himself, and has a companionable conversation with Death, who is now back on duty.
“And with great relief, and general optimism, and a feeling that on the whole everything could have been a lot worse, Windle Poons died.”
A couple of Windle's many years are in doubt, since the Discworld Timeline says he was born in 1857, but died aged 130 in 1985 (128 years later).
The words with which Windle Poons excuses himself from the luncheon the Wizards are giving the Fresh Start Club — 'I'm just going out, I may be some time' — are almost identical to the last words of Captain Lawrence Oates, uttered just before walking out to die in the Antarctic night in the hope his companions would survive if they didn't have him to slow them down. They didn't. This is almost certainly not coincidental.
His final words alive (pre-zombie) were 'I think I could eat one of Dibbler's meat pies.' This is a reference to former British Prime Minister William Pitt the Younger, whos last words were 'I think I could eat one of Bellamy's veal pies.'
“You know”, said Windle, “it’s a wonderful afterlife.” (Corgi PB, p. 283). This evokes the 1946 film, It's a Wonderful Life (1946 - see Wikipedia). James Stewart plays a man who is about to commit suicide on Christmas Eve by jumping off a bridge. His guardian angel intervenes. He is shown what life in his town would be like if he hadn't been born, and chooses to live.