Summoner Name ( Blob ) has slain Baron!

[Gameplay] : (Blob) instead of Champion name.

When I was playing league with some friends, I stole Baron. My friend pointed out that it said "(Blob)" instead of "(Lee Sin)" next to my name. I went back into replay to capture this screenshot, but I have no idea why it says Blob. We thought it was hilarious but got really curious. I tweeted the image and explanation to Riot Games Support on twitter, but they were just as confused and told me to post about it here. An explanation would be great if anyone knows what happened. This is the only time I've ever seen this happen though.