"Terrifying."

That's how Will Ferrell described portions of last week's attempt to play all nine positions in Major League Baseball in a single day.

Will Ferrell To Attempt Hilarious MLB Spring Training Feat

The Anchorman and Talladega Nights comedy star stopped by The Late Show with David Letterman on Tuesday -- dressed in full St. Patrick's Day regalia no less -- to discuss his impressive stunt.

"There were moments that were terrifying, I'm not going to lie to you," Ferrell said to a bemused Letterman. "Trying to hit a 90 mile-per-hour fastball is next to impossible."

The 47-year-old played for ten different teams and commandeered all nine positions over the course of the day. Ferrell traveled from stadium to stadium by helicopter, switching jerseys practically on the fly.

NFL Legend John Madden BLASTS Will Ferrell Over MLB Stunt

If all of that sounds self-indulgent and stupid to you, well, you should at least appreciate that it was for charity. Ferrell's website Funny or Die raised over a million dollars in the fight against cancer for the stunt.

Watch Will Ferrell discuss his Spring Training escapades below: