Read more - Robert Downey Jr and Zach Galifianakis unite for hilarious performance-SEE VIDEO

When they first met, Robert Downey Jr thought that Zach Galifianakis was a hobo.

According to the Irish Independent when the comedic due for the new movie "Due Date" met Downey was surprised by Galifianakis' unkempt appearance. The 45-year-old actor assumed the that "Hangover" funny man was a crazy fan and did not recognize him.

Speaking on the red carpet at the London Empire, in London. Downey Jr's wife, Susan said "It was on Main Street in Venice Beach and he comes up - the problem with Robert is he doesn't recognize anyone's face - so I recognized him, and I'm like: 'This is not going to go well,' and he comes up and he's like: 'We're doing a movie together,' and Robert was just ready to, like, just, twok the guy."

Robert said "He looked he might have been sleeping in a cardboard box somewhere to me."

Galifianakis admitted that he wasn't looking his best when they met. He said "Yeah, unfortunately, I went up to him and the way that I looked I think he was a little shocked that a hobo was telling him the two of us were going to be doing a movie together."

Read more - Robert Downey Jr and Zach Galifianakis unite for hilarious performance-SEE VIDEO

Here's a clip of other goings on at the premiere: