Cee Lo Green, who is back on 'The Voice,' has never been shy about expressing himself.  He's known for his crazy costumes in addition to his unique voice.  But what the heck has he done to his head? Blake Shelton may have the answer.

The tattoo on Cee Lo's head is actually a henna tattoo.  Blake says 'It's not permanent. The last time I saw him, it wasn't on there.'

The henna tattoo is probably one of the tamer things Cee Lo has done.

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'Thank You' Volunteer Fire Fighters From Cee Lo Green [VIDEO]

Blake Shelton's fellow judge on NBC's " The Voice" Cee Lo Green is thanking the men and women who risk their lives every day. He re-worked his hit song " Forget You " to "Thank You" for volunteer firefighters. He's even included great shots of firefighters on the job throughtout the video.