A mix of onion plants and garlic plants; or a single plant that was supposed to be some sort of combination/dual-use?
A mix of onion and garlic. He planted them in TWO different places, and it seems that he mixed them in together. Or they just hopped around as they rapidly multiplied.
I decided to let some stay through this season to see if they produce anything edible - but now I am regretting this decision. And digging up a bunch. I am putting them on the stream bank - they will be brilliant there for erosion control.