Ben

Ben is Ross and Carol's son. He's raised by his two mothers, Carol and Susan, but also spends some time with Ross, who introduces him to the Jewish tradition, like in the one with the Hanukka, when Ross tries again and again to make Ben interested in the Jewish stuff, he even dresses himself as a (in Chandler's words) "weird turtle-man", hahahaha. Actually Ross's costume pretends to be the Holiday Armadillo, a kind of Santa for the Jewish or something.

ROSS: So, Ben, you uh, you know what holiday is coming up, don't ya?
BEN: Christmas.
ROSS: Yep, and you know what other holiday is coming up?
BEN: Christmas eve.
ROSS: Yes, but also... Hanukkah! See, you're part Jewish, and Hanukkah is a Jewish holiday.
BEN: Santa has reindeers that can fly!
ROSS Right, um, but, on Hanukkah, Hanukkah is a celebration of a miracle. See, years and years ago there were these people called the Maccabees...
BEN: (singing) Jingle bells, jingle bells...
ROSS: (interrupts him) Okay, that's right, yes, but on Hanukkah, uh, we sing, uh Dreidel, dreidel, dreidel, I made you out of clay.
BEN: (singing) Rudolph, the red-nosed reindeer...
ROSS: (interrupts him again) Okay, it's not a contest.

Ben seems to be a naughty boy, that likes to play and have fun with adults. Rachel knows that's right... check out this 5 minutes long video, it's worth to see:



And in the next video (a interview to Ben) I love when he says:
"My favorite cast member to do scenes with is Jennifer... Cuz shes hot!"