Mr. Gruber is the Hungarian elderly owner of an antique shop on Portobello Road, and a friend of Paddington's, whom he calls "Mr. Brown." He usually takes Paddington and the Browns to outings. He has taken Paddington to places such as the Tour De France and Japan.
He is currently writing a book called "The World and its Wonders" which explains why he takes Paddington to places. Paddington helped him by finding interesting things in France.