Question: who are the jibber jabber twins?
Answer: Jibber and Jabber: The titular protagonists of the series, Jibber and Jabber are seven-year-old fraternal (non-identical) twins. ... 
Jessica: Jibber and Jabber's older sister, who usually figures as an antagonist in the boys' imaginary adventures. ... 
Jelly Roll: Jibber, Jabber and Jessica's dog.