Alan and Walden will face off to earn the title of "the world's greatest dad" in Thursday's episode of "Two and a Half Men."

In the last episode, which aired on Thanksgiving, Ms. McMartin placed a 6-year-old foster child named Louis with the roommates for the weekend and told them that if everything worked out, they could officially adopt him. However, she warned that Louis might come across as shy since he's been moved around in the foster care system, reports Entertainment Weekly.

Walden quickly became overzealous about the idea of caring for a foster child and filled his home with lots of toys, a tube slide, large stuffed animals, a gumball machine and arcade games.

That's when Alan stepped in.

"If you build Disneyland in your house, you'll never get the thrill of taking him to Disneyland," he said.

The next day, Louis arrived at their home and immediately asked if they have any Cheez-Its. However, other than that, Louis did not have much to say and came across as very withdrawn and aloof, despite Walden's desperate attempt to make the little boy like him.

Eventually, Louis warmed up to Walden. He began chatting away once he realized that he likes living in their home and will not have to leave.

Louis will also be featured in the next episode, which is entitled "Alan Shot a Little Girl." A preview shows that the best friends will fight to be Louis' favorite parent.

"Louis thinks I'm Al Al Cool Dad," says Alan in the clip.

"You're not!" cries Walden in response. "You're just Weird Al."

According to Carter Matt, the synopsis states that: "When Alan realizes Louis thinks he's cool, he starts breaking Walden's rules in order to stay that way."

Season 12 Episode 6 of "Two and a Half Men," "Alan Shot a Little Girl," airs on Thursday, Dec. 4 on CBS.

Watch a preview video here.