I think you're getting confused. 'Marathon' is what they were called before Michael Grade cancelled the show. In Russell T. Davies's and Steven Moffat's brave new Who, they changed to 'Snickers', in an attempt to be down wiv the kids (who lack a classical education) and appeal to the American market. The special effects on the peanuts are much more realistic now, although I preferred it when the Doctor took four episodes to devise a fiendishly clever solution to foil the Marathons' plans. (Like for example in the classic story "Meltdown", when the Doctor melts the Marathon invasion force by turning the thermostats up on their starships.) Nowadays, he just waves his flipping sonic screwdriver at them and they become Bounties.