Aunt Coleta is first mentioned in the 1981 album Bert en Ernie Vervelen Zich Nooit... In the 1984 album In Een Uur de Wereld Rond, Uncle Rudolf explains that his wife has left him, at which point he took up with a girlfiend. The couple later reconciled, and Aunt Coleta made her first speaking appearance years later in He He He, We Maken Muziek (1996). She lovingly refers to Rudolf as "Rudi-pudi." She plays the violin and sings, accompanied by Rudolf on the grand piano.