"Moose mints" origin
Word plays on the excrement of indigenous moose are common everywhere moose are common. In Alaska, we often refer to "Moose Nuggets" both as novelty food items and as (I kid you not) novelty jewelry items. Moose excrement is much like rabbit excrement in that it comes in big piles of perfectly shaped, tiny turds. 





There is a company out of Spokane, Washington that sells Moose Mints:



It's the same kind of silly word play/scatological humor. There is no particular type of candy or kind of mint involved, it's just meant to be cute play on the rather bizarre (and therefor "funny") nature of moose poop.