Tikes

Toddle Tots are a set of toys directly taken from the Little Tikes company. They make brief appearances with Andy's toys throughout Toy Story and Toy Story 2, and are mostly heard making a high pitched squeak. Many of the Tots include the Fireman Tots in their Toddle Tots Fire Truck, along with Cap Toddle Tot, Farmer Toddle Tot, Doc Toddle Tot, Hunter Toddle Tot, Painter Toddle Tot, Sailor Toddle Tot and a Shriner Toddle Tot in a little red car.

Toy Story
In Toy Story, the Toddle Tots can be seen at the very beginning of the movie when Andy was playing with his toys. They're also seen afterwards when Woody was having a staff meeting, and later on when Woody and Buzz were chasing after the moving van.

Toy Story 2
In Toy Story 2, they can be seen looking for Woody's lost hat along with Mr. Shark and the Green Army Men. Also, some more Toddle Tots were listening to Mrs. Potato Head read a book to them. The Shriner Toddle Tot was used in a re-enactment of Woody's kidnapping from Al, playing the role of his car, to help Hamm figure out which direction he went. They're last seen at the end of the movie when Wheezy was singing "You've Got a Friend in Me".

Toy Story 3
Toddle Tots and the Toddle Tots Fire Truck do not appear in Toy Story 3. It's very likely that they were sold in a yard sale, donated or given away over the years due to being the toys from when Andy was a toddler.

Buzz Lightyear of Star Command: The Adventure Begins
In Buzz Lightyear of Star Command: The Adventure Begins, five of the Toddle Tots come over to watch the movie with all of the other toys.

Trivia

 * Although they never appear to talk in the films, two of the Fireman Toddle Tots do have speaking roles in the Toy Story Animated StoryBook game. When you click on them to help Woody and Buzz onto the moving van they say "Get real, we have no arms!", and in the Christmas ending one of the Tikes gives the other one mittens for a present, who then says "Just what I needed."
 * In the Toy Story Activity Center, Slinky Dog watches the Toddle Tots being used in a game against the Green Army Men called "5-in-a-row".
 * The Toddle Tots appear as a mission in Toy Story 2: The Video Game. There are five of them scattered throughout a level that Buzz must find in order to earn a Pizza Planet token. This type of mission is also used for the Green Army Men, Aliens, and Bo Peep's Sheep, but is used for the Toddle Tots more than once.