I thought Coco Krispies and Coco Pops were the same thing. One is just the British version.
Coco Pebbles are flatter, flakeir and have more chocolate in them than Krispies (which are basically just chocolate Rice Krispies)
Coco Puffs are the round, puffy balls which I go Cucco for

--Chocolate Cereal Connoiseur Extrodinair--