Todd's Canada Goose Branta canadensis interior
This form of Canada Goose reguarly turns up in the UK from North America, tyically among Barnacle Goose or Pink-footed Goose flocks. Identification of lone individual vagrants is difficult and some individuals are probably best left un-named with different experts reaching different conclusions.
Todd's Canada Goose (with Barnacle Geese), Cardurnock (Cumbria, UK), 28th December 2013
I think the majority opinion for the next bird was Todd's but some observers felt it was more likely to have been a Lesser Canada Goose (parvipes).
probable Todd's Canada Goose (with Pink-footed Geese), north of Stanhoe (Norfolk, UK), 8th January 2004