Spearmint is a game character idea: a single mint leaf, barely bigger than a thumb, who has claimed one branch of the tree as its own and will not be talked out of it.
It carries a spear whittled from a twig, mostly for show, but it will use it. Most things that cross the branch are bigger than Spearmint. None of them seem to notice.
The idea is a tiny, over-confident guardian — the kind of character that turns a small corner of a world into a boss fight over principle, not size.