While Old Gnawbone's ability requires creatures to deal combat damage, thanks to the wording of its ability, Klauth is still able to provide significant sums of mana, even if it's blocked
The goal is to build a consistent, powerful deck with the cards, and is one of the most addictive elements of the game given the wide variety in decks and strategies that come out of the format
Mickey is also cheaper, inkable, and the accompanying Brooms allow you to return cards from your discard pile back to your deck providing insurance against decks that aim to win through deck out (more on this later)
While it isn't the most innovative creature design-wise, it sure is powerful
however, the English version is notoriously difficult to find with clean centering, making high-grade yellow-border copies exceptionally valuable to collectors
If your hand is really bad, this can even be used as a mulligan to help fix your hand