Axe
From Wild World Wiki
The Axe is one of the basic tools available from Tom Nook's store. He will sell it to you for 400 Bells. The axe is used for cutting down trees (leaving tree stumps behind). After being used for some time, the Axe will break.
By completing a trading sequence you can recieve the upgrade, the Golden Axe, which functions in the same way as the regular Axe, but will never break.