Hippo and Duck are the mascots of British bed manufacturer "Silentnight" and have been since 1986.
Hippo is depicted as a male hippopotamus wearing blue and white striped pyjamas whilst Duck is depicted as female and has yellow duckling feathers, despite being an adult.
In adverts that first aired in 2001, Hippo and Duck are seen preparing to go to bed and describe what the beds Silentnight have and what is in the mattresses. An advert in 2003 for "My First Bed", featured Hippo having two sons named Hugo and Henry, whilst Duck has a daughter named Dee-Dee. At the end of the adverts, Hippo will say "Sleep tight" and Duck says "Have a silent night".
In these adverts, Hippo was voiced by Clive Rowe and Duck was voiced by Jane Horrocks.
Hippo and Duck were originally traditionally animated, but since 2010, they have been computer animated.
They have also appeared in Silentnight's sponsorship adverts for ITV drama series Where the Heart Is and UK broadcasts of American Idol.