Focuses on a group of toddlers, most prominently Tommy, Chuckie, Phil, Lil, and Angelica, and their day-to-day lives, usually involving common life experiences that become adventures in the babies' imaginations. Adults in the series are almost always unaware of what the children are up to; however, this only provides more room for the babies to explore and discover their surroundings.
After Tommy is found drawing on walls at the Pickles' house, Stu and Didi take him to a psychiatrist name Dr. Lepetomaine. When Tommy breaks free and has an adventure around the medical office building, Stu ends up being the one psychoanalyzed.
After seeing a scary movie, Tommy and Chuckie decide to find out if Stu is a human or robot. Too bad his sleepwalking makes him appear to be a mechanical monster!
When Stu orders a "Tina Trousers" doll from Eggbert Toys to see how it compares to his own "Patty Pants" design, Tommy think the Pickles' are getting a new baby in the mail. Hitching a ride with the mailman, Tommy ends up exploring the post office.
The Pickles family sets up a haunted house for Halloween, and Angelica is determined to find all the Reptar Bars. But when the Rugrats go searching for them as well, will they end up scaring her off?
When Spike is accused by Stu of knocking things over in the Pickles' garage, the Rugrats go to investigate what really happened and clear Spike's name. Believing it to be a monster, will the babies be brave enough to discover who the real culprit is?
On advice from Dr. Homer, Tommy's dentist (Didi prefers calling him a "tooth fairy"), Stu and Didi want Tommy to start drinking from a cup. Tommy, however, wants to stick with the baby bottle.