Digby, the Biggest Dog in the World is a 1973 British children's fantasy-adventure comedy film starring Jim Dale, and directed by Joseph McGrath.

[2] A large supporting cast of British movie stalwarts includes Spike Milligan, Angela Douglas, Norman Rossington, Milo O'Shea, Dinsdale Landen and Victor Spinetti.

He steals a tiny amount of Project X, but an Old English Sheepdog accidentally drinks it.

X is a liquid growth formula (a form of experimental fertilizer) and Digby expands to gigantic proportions.

Authorities and scientists scramble to find a way to shrink Digby back to normal size before he causes more destruction.