Derek (Code of the Krillitanes)

Derek was a supermarket worker in London, in the year 2010. When the Doctor approached him to ask where the crisps were, Derek was rude and grumpy. When the pair reached the aisle with the Brainy Crisps in it, Derek was annoyed and confused as to why the Doctor needed all the packets of crisps. When the trolley the Doctor had was full, Derek was ordered to go and get another one. (NSA: Code of the Krillitanes)