The jester off rentaghost, think he was called mr claypole. Everytime my mum warned me about strangers I got a mental image of him and it scared me to death lol
I also remember an amphibian with a machine gun in Fireball XL5. It was wlking towardds a building in which two grey-haired men were waiting for a lift to take them to the basement, and safety. The camera kept switching between the amphibian and the lift indicartor which was purple fluid in a tube moving as the lift got closer. They made it, just!
I must have been about five or six, but it has really stuck in my mind.