I'm pretty darn sure about it being a calamint at least. Square stem, tubular purple flowers.

It showed up in my yard and has seeded around a good amount. It fits most photos of Nepitella (although some photos show a shinier leaf).

The flowers are lavender and tubular, exactly like most online photos for Nepitella. I have looked for my own photos of it blooming with no luck so far.

Does anyone know of other possibilities for it? There's no harm in tasting it since it's in the mint family, right?