Seth Macfarlane has no "good reason" to stop making 'Family Guy'.

The 50-year-old comic launched the aminated adult comedy series on Fox in 1999 and it ran for three seasons before being axed, only to return to the network in 2005 following the popularity of reruns and DVD sales, and the show's star and creator is thankful for the money it makes because he can donate a lot to charity.

He told the Los Angeles Times newspaper: “At this point, I don’t see a good reason to stop.

People still love it. It makes people happy and it funds some good causes. It’s a lot of extraneous cash that you can donate to Rainforest Trust and you can still go out to dinner that night.”

But Seth admitted there was a previous point where he thought it was "time to wrap it up", but he will no longer consider it unless viewing figures drop.

He said: “There was a time when I thought, it’s time to wrap it up. At this point, we’ve reached escape velocity. I don’t know that there’s any reason to stop at this point unless people get sick of it. Unless the numbers show that people just are, ‘Eh, we don’t care about Family Guy anymore.’ But that hasn’t happened yet.”

Both Seth and his co-star Alex Borstein admitted they didn't expect the show to still be producing new episodes 25 years later.

Asked her memories about when she was first offered the show, Alex said: "It was sketch comedy mixed in with a sitcom and it was so dense. Each episode had so much in it, and I just knew it was special and weird and made me laugh out loud, throughout.

"But I had no idea it would be 25 years. None whatsoever.

"Sorry [Seth]. Not that I didn’t trust you."

Seth added: "I didn’t either. I prayed to God every night that it would be 10 years and out."