Self topping seedling?

Has anyone seen this? This is my fifth grow so I'm still pretty new...if anyone has encountered this, what's going on? And if this is common, feel free to laugh at me

not common, but also not rare. self toppers usually have a damaged or defective/deformed node causing an effect similar to topping, what you have appears to be a twin.

twins are rare, but not entirely uncommon. perhaps one in 10,000 (guesstimate)

Very cool. I'm only running SOG in 1 gal pots so space and numbers aren't an issue, I think I'll see what she can do. If I was keeping fewer plants and letting them get big I think I'd probably cull her.