Methone
I haven't been keeping up with Cassini, so the first time I saw a photo of this moon was in my Planetary Report magazine.
Check it out:
Okay, that's a bit weird. Giant monster egg? Niven Starseed? Spaceship? Or just a blob of loosely-organized dust (the current theory)?
I'm assuming that the long axis of the "egg" runs through the middle of Saturn, and the shape of the "dust ball" is due to tidal forces. I don't know if anyone has estimated the mass.