Why The Dolan Twins' Dreams Are Finally Coming True

It all boils down to one 'Factor'

For the Dolan Twins, appearing on MTV's Fear Factor isn't just a chance to face their phobias -- it's also the fulfillment of their biggest fantasies.

"This is like two childhood dreams colliding," Ethan Dolan says in the Fear Factor bonus clip, below, as his brother Grayson nods in agreement. "We love Jackass, we love Fear Factor. It's like both happening today."

The twin with the dark hair -- well, at least since Grayson went blond in December -- goes on to reveal what scares him the most.

"I think my biggest fears are big, exotic animals," says the Youtube/Vine/TRL star. "We're good with bugs, tight spaces, the dark."

So will Ethan face any unusual animals -- you know, like ostriches -- on the celebrity edition of Fear Factor? Watch the clip to find out, then catch the Dolan Twins' episode on Tuesday beginning at 10/9c.