Sampo

Sampo is a brand of artificial fruit seen in "Happy Anniversary." D.W. wanted to eat some, but Arthur couldn't open it without a can opener. It was later discovered that the cans are made of tin-- the very thing that D.W. was searching for through the whole episode.

Trivia

 * Normal "tin" cans are actually made of other metals, (or tin coated with other metals) because acidic foods like pineapple will corrode tin. Since the cans are actual tin, the fruit may be contaminated. Then again, it is artificial.