Dragons at Crumbling Castle by Terry Pratchett

Dragons had invaded Crumbling Castle whilst all King Arthurs’ knights were away on holiday or visiting their Grannies. Ralph a small boy found a suit of armour and was eager to wear it and so together with Wizard Fossfiddle and Fortnight the Friday knight they set off to defeat the fire-breathing creatures. Chaos and surprises to follow. Funny events abound and other stories include Time Travel to monsters and even tortoises!