Update:
Didn't plant mint, after being warned off due to its invasive nature... though I wonder if it would invade my garden. My raised bed is 8" above the rest of the yard ground level, and I was planning on planting it outside of the raised bed. It's just bare earth, and it would end up drinking whatever water made it from the garden's irrigation system into the ground around the garden. I wouldn't deliberately water it otherwise. Should keep it starved, and otherwise unable to climb back into the garden.
I got 1/4" hardware cloth. Put it around the perimeter. Seems to be doing the trick. I have new tomato seedlings coming up now, my peas are slowly coming back to life, and my corn has been left alone.
Never got the little bastage that started the trouble, unless he died from his struggles with the sprung mouse trap later on.