Seeds have sprouted while still inside this tomato. The word botanists use to describe this is vivipary. It isn't that rare, really. However, this is the first time I've actually seen this where the sprouts make their way through the skin.
There are little 'bumps' on the tomato (you can see them in the picture) -- this is where the seeds have sprouted and are trying to find a way out.
Thanks to Sandy for bringing this oddity to my attention!
Plants are so cool.
