Speaking to Jamie Redknapp on Sky Sports, the 27-year-old Mount was asked to name the dressing room comedian.
"I don't want to say it, but it is Ayden. He is just silly. He is a youngster and he is silly about everything. But you need that around the place and it keeps it very light at the training ground, but sometimes he needs to be put in his place and that happens. But he's a really good character."
Heaven, 19, joined Manchester United from Arsenal in the summer of 2025 and has made 18 appearances this season. The central midfielder has been one of the more encouraging developments of an otherwise turbulent campaign, impressing enough to earn a training call-up with Thomas Tuchel's England senior squad in March.
On future managers within the squad, Mount did not hesitate.
"There is definitely someone who comes to mind — I think Tom Heaton. When we go away on trips, he has got his laptop out doing clips and stuff of the opposition and goalkeepers. He is really into it, and I definitely think he will be up there."
Heaton, 38, has made six appearances this season as backup to Senne Lammens. He earned widespread praise in the dressing room early in his career for his preparation and tactical curiosity, qualities that have only deepened in his later years as a player.
Mount also revealed that Bruno Fernandes and Harry Maguire are not shy about making their feelings known during games — a portrait of a dressing room with no shortage of strong personalities beneath the laughter.
Since Mount returned to first-team duties under Michael Carrick after a lengthy injury absence, United have not lost in the league — a run that has secured Champions League qualification ahead of the final weekend.