He appeared in character for his Casey Affleck-helmed mockumentary 'I'm Still Here', which saw Phoenix quitting acting to pursue a hip-hop career.

The actor was promoting the mockumentary 'I'm Still Here' when he delivered one of the strangest interviews ever recorded for late night television.

On Tuesday night, the star said that he originally did the pre-interview in character and “I realized that it was just a little silly, so I called them back and I said, ‘Listen, this is what I’m doing. I’m coming out here and I’m doing this whole thing.’”