Catherine Tate's Nan character causes chaos on the wards of Holby City when she is revived for a one-off sketch for BBC Children In Need.
The comic actress is the patient from hell in the short film to be screened during the BBC1 appeal show on November 15.
It sees Nan - who was one of the most popular creations who featured in the Catherine Tate Show - reunited with her grandson, played once more by Mathew Horne.
Catherine said: "Thanks to everyone at Holby, I'm happy to be involved with Children In Need this year."
The sketch also features well known Holby faces including Tina Hobley as Chrissie Williams and Hugh Quarshie as Ric Griffin.
Hobley said: "Over the years Holby City has faced flooding, riots and hostage situations - but nothing quite prepared us for the arrival of Nan".