Frank Blossom is the caretaker at Cackle´s - but he´s also a great inventor of all kind of contraptions - broomstick flight simulators, alarm systems and Patent Painless Cheeseprotectors included. Unfortunately, most of his inventions won´t work - and even if they happen to do so, the staff won´t appreciate them - and for the pupils they are merely a source of great mirth. Still, Frank never gives up working out elaborate machinery to make the life at the castle less medieval..
Mostly he is engaged, though, in trying to prevent the castle from crumbling to ruins. Rusty drains, fungus growing under the beds, creaking steps and shaky pillars offer a wide range for do-it-yourself work - and in between there´s piglets to catch, kittens to distribute or monkeys to chase...
Frank has got two brothers - Ted, who takes over the caretaker´s job in season 3 when Frank moves to Horticulture college (being a passionate gardener and great admirer of well-grown marrows) - and also another nameless brother whose son Charlie pays repeatedly visits to the Academy (and has quite a crush on Mildred...)