"Scooby Dooby Doo ... where are you?" asks one colourful postcard, illustrated with five familiar cartoon characters and posted through the home mailboxes of persistent truants.
Another postcard is even more to the point: a satellite photo of the local area features a giant arrow pointing to the school. "We are here," it reads.
Mike Griffiths, the principal, said formal letters to parents are often ineffective.
"A standard letter, with official-sounding jargon, often goes straight into the bin when it reaches home, so we thought we'd try a different approach," he said.
Parents' views are mixed, however. One mother, whose 15-year-old daughter often plays truant, said the postcards were "pathetic".
"We would kill ourselves laughing if we got one of the cards," she said.
But if Scooby Doo and his pals collar a few truants, Dr Griffiths will not be complaining.