Bo Jakobsen

as Benny (voice)

Jesper Klein

as Tadpole (voice)

Peter Belli

as Octopus (voice)

Jytte Abildstrøm

as Dagny (voice)

Otto Brandenburg

as Lobster Boy (voice)

Jytte Hauch-Fausbøll

as Benny's Mother (voice)

Rolf Krogh

as Ornithologist (voice)

Povl Dissing

as First Pirate (voice)

Per Bentzon Goldschmidt

as Second Pirate (voice)

Per Tønnes Nielsen

as Cowboy (voice)

Aya

as Mermaid (voice)

Maia Årskov

as Mermaid (voice)

Trille

as Mermaid (voice)

Christian Sievert

as Crab (voice)

Allan Botschinsky

as Seahorse (voice)