Odd corrosion for what I assume is copper? Could be that it got splashed with something acidic, but if I were a guessing guy it's from a loose/improper grounding connection to the terminal. Loose grounding increases resistance and will start to cause aggressive pitting on the terminal.

Depending on the battery company, a loose grounding wire may be covered under warranty. A battery meant for transportation should be expected to hold up to vibrations and activity that normally knocks wiring around.

If not replacing a terminal should be pretty easy even if you have to make one yourself, but make sure to look up a diagram of the battery and make sure you wired it correctly.