ABC News' Anna Wild reports:
MacFarlane, 39, spoke with "Good Morning America" correspondent Amy Robach about the big night.
In the interview, which aired Thursday on "GMA," Robach asked MacFarlane what superlative he thought would be used to describe his job as host.
"Gosh, I don't know," he replied, adding, "Most astonishingly dazzlingly mediocre?"
Despite his self-deprecation, MacFarlane is a huge talent. He co-created the hit shows "Family Guy," "American Dad!" and "The Cleveland Show," and provides several of the voices.
Asked about his talent for voices and whether they served as a creative outlet for him, he laughed and replied, "Yeah. Yeah. I'm like a male, you know, Martin Lawrence. You never know what's going to come out when and what form it'll take and how dangerous it'll be."
MacFarlane made his feature directorial debut this past summer with the box office hit "Ted," which he co-wrote and produced, while voicing the title character, and he is an Academy Award nominee in the Best Original Song category for "Everybody Needs a Best Friend," the theme song from the movie.
He said he was "genuinely excited" about the nominated, but added, "I know we're going to lose to Adele … ."
British singer Adele is also nominated in the Best Original Song category for the song "Skyfall," from the latest James Bond film, also titled "Skyfall."
Awards show hosts are often criticized for being too conservative or going way too far in their comedic routines. MacFarlane revealed that nothing - and no one - will be off-limits to him as possible targets for jokes.
As for MacFarlane's favorite Oscars host? "You know, I think - I think Johnny Carson is probably the … gold standard," he said.
The 85th Annual Academy Awards will broadcast live Sunday on ABC.