ALL 410 pupils at Bridgewater Middle School in Bridle Way, Berkhamsted, wore fancy dress on Friday.
There were tigers, penguins, cows, gnomes, fairies, zombies, a pair of Scooby Doos and a gorilla.
Their five-kilometre fun run was delayed until Monday due to the wet weather.
But headteacher Rachel Swaffield said: “That didn’t dampen spirits.”
Youngsters raised £58 by baking and selling cakes. Mrs Swaffield hopes more than £3,000 will be raised in fun run sponsorship.
Buy a copy of the Gazette this week for a picture spread of school Comic Relief fundraisers.