Hmm... you stand more chance of finding Tux stuff online.
Really, your best bet is to get your Dad to drop in to Olympia in the next couple of days & see what's on offer at the various stands at LinuxWorld. It should be a good show anyway.
You might find a stuffed penguin at Hamleys (Regent Street, I think), or any good toyshop. Hint : Pingu is not dissimilar to Tux and is likely to be easier to find