Up the front (1972)

In Frankie Howerd's third Up... film it's World War I and he plays Lurk, an absolute cowerd, er coward. He's evading the call-up for all he's worth. But one evening he's hypnotised by a drunken hypnotist (Stanley Holloway) into being brave, but he fails to be released from it. So with his yellow streak gone Lurk is down that army office before you can say "titter ye not." Off to war he goes, mingling with sexy spies like Zsa Zsa Gabor and before long, the spellbound recruit is heading hot-foot back to Blighty with the Germans' plan of attack tattooed on his bum, and the Germans are bringing up the rear...! Full of sauce, knowing real-life references and witty remarks to camera, this is a cheeky incorrigible final instalment.