Bullseye the horse is the first toy with which Woody interacted in Al's penthouse. He was extremely happy to finally see Woody over a long time in storage. When Woody found a shelf full of collectibles of him and his roundup gang, Bullseye jumped to the record player while attempting to catch a toy snake fired from a toy boot by Woody. When Woody loses an arm, he attempts to get his arm back from Al, who is sleeping with a fallen bowl of scattered cheese puffs everywhere. Bullseye joins in and tries to help him. Woody told him to go and reminded him he's trying to get him to storage, but Bullseye licks him and wants to help, so Woody allowed him to. But he licked Al's cheesy fingers, but stopped when Woody told him to stop. Bullseye is shown to loathe fights as he hides in a can when Jessie jumps on Woody. He is also upset at Woody's intention to abandon the Roundup gang to return to Andy. Bullseye doesn't want Woody to leave and sadly looked at him when he stared at the vent, which is the way out. But Bullseye grins when Woody decides to stay with the gang. Later when Woody was doing an introduction, he called Bullseye to ride like the wind, but his saddle fell, making him move out, embarrassed. When Buzz and the toys find Woody, Slinky tangled Jessie and Bullseye so they could grab Woody and run. But Woody refused to join them, but later did. When Woody ultimately decides to return to Andy's room, it is Bullseye's loyalty that causes Woody to try to get the other toys to join him. At the airport, after Bullseye escapes from Al's case, Woody and Buzz Lightyear mount Bullseye and gallop across the airfield to rescue Jessie from being sent to Japan. Although Woody gets separated from Buzz, Buzz commandeers Bullseye to follow Woody, as they are seen galloping next to the wheels of the plane Woody and Jessie are on as it heads down the runway. The mission finally ends when Woody and Jessie swing down from the plane and land on Bullseye back right behind Buzz, seconds before the plane takes off. After the toys return home, both Bullseye and Jessie come along as part of Andy's toys. Bullseye has every letter of Andy's name printed on the sole of each of his hooves. Bullseye happily watches Wheezy sing "You've Got a Friend in Me." Bullseye returns in Toy Story 3 as one of the remaining toys in Andy's room. He is still Woody's horse in the opening sequence and saves him when he falls off the train by One-Eyed Betty. Bullseye's fast speed helps Woody catch the train and rescue the orphans. Bullseye is really sad when Andy wouldn't play with them anymore. After Andy's mom thought the bag the toys were in was trash, Bullseye and the toys manage to safely hide in a recycling bin. The toys are donated to Sunnyside Daycare. At Sunnyside, he proves his loyalty to Woody when he makes clear he wants to stay with him. He only stays when Woody tells him to since Woody doesn't want him to be alone in the attic. Bullseye is roughly tumbled over by a screaming toddler with a rolling wheel toy. After the toddler play session, Bullseye is covered with paint and has a blue sticker in his snout, which is removed by Jessie. When Lotso is revealed to be evil, he locks the toys up and shows them Woody's hat, making Bullseye miss Woody and sad he's gone. Bullseye is extremely happy when Woody comes back to Sunnyside and gives him back his hat. The toys plan an escape. Bullseye helps by going through the playground, carrying the aliens on his back. He goes with Woody and is almost caught by Big Baby when Bullseye jumps and accidentally makes an alien fall and squeak. But they hide inside a pail. The toys then go to the garbage dump, and Bullseye is the most desperate to escape the incinerator. They are rescued by the three aliens. At the end, Bullseye is donated to Bonnie, along with the rest of the toys. In Bonnie's room Bullseye changes the channel of a radio to a Spanish channel causing Buzz and Jessie to dance to the Spanish version of "You've got a friend in me." Bullseye acts like a dog in many ways. Unlike most of the other toys, Bullseye cannot communicate in clear speech but sounds like an actual horse and uses body language to speak. According to a character interview that used to be on the Toy Story website, Bullseye communicated with Jessie while in storage by tapping his hooves to yes or no questions.

Bullseye reappears in the short films Hawaiian Vacation and Small Fry. and will return in Partysaurus Rex.