"I'm the Big One Now" is a Sesame Street song sung by Jerry Nelson over footage of children and their baby brothers and sisters playing together. On the album version, Nelson's lead vocal is replaced by Paul Jacobs, credited as "A Young (but Growing) Boy" with backing by The Oat Bran Zydeco "Je Ne Sais Quoi" Band. In A New Baby in My House, the three older siblings in the song are said to be named Tony, Tasha and Carlos.