The Finnish and Swedish version of the onomatopeia moo.

Also the name of a milk beverage from the big European dairy product company Arla. It's sold in 2dl cartons, has the fat content of 1.5% and comes in three flavors: chocolate, banana and strawberry.

Although the drink itself is nothing that special - the banana version tastes downright awful, and the price is quite high - the product's name is simply the best ever.
Who couldn't resist a carton with a cute drawing of a happy cow and the word MUU planted in big letters right above it? Is that just the silliest thing ever? The whole naive and innocent design makes me want to smile every time I see a boxes of Muu on the shelves.
This must be planned through very carefully, since a package of pork chops with a colourful Oink logo would not have nearly the same effect.