Lots-o'-Huggin' Bear

Lots-o'-Huggin' Bear, better known simply as Lotso, is the main antagonist in Toy Story 3. His voice was performed by Ned Beatty.

Past
According to Chuckles the Clown, Lotso was originally a teddy bear owned to a girl named Daisy. However, one day when She took Chuckles, Lotso, and Big Baby (a giant baby toy) on a picnic, she left them behind by accident, and considered them to be lost.

Chuckles, Lotso and Big Baby found their way back to Daisy's home, but there Lotso finds that he was replaced by another copy of him to Daisy. This left Lotso heartbroken as Daisy no longer wanted him anymore. Big Baby tried to return back to Daisy's house, but Lotso refused to let him, claiming she'd replaced them all, Lotso ripped and threw a toy heart Big Baby had hanging from his neck with Daisy's name on it, which Chuckles recovered and hid.

After that they climbed up Pizza Planet deliver truck and fell at Sunnyside Daycare Center. Lotso got his leg injured, Big Baby got deformed his face and Chuckles broke (or start braking). There, he had gathered minions to follow his code of tormenting other toys into being tortured by the daycare infants. He turned Sunnyside into a pyramid where he'd be the head, and would rule in tyranny the daycare center threatening the toys with spending the night in the box (the sand box), being harmed by his minions or by the kids in the caterpillar room who were too young to know how to play properly with them.

Chuckles ran lucky when he got broken, Bonnie found him, took him home and repaired him.

Toy Story 3
In Toy Story 3 when Andy was all grown up, his toys Woody, Buzz Lightyear, Bullseye, Jessie, Mr. and Mrs. Potato Head, The three Little Aliens, Rex, piggy-bank Hamm, Slinky, and Barbie all went into Sunnyside by accident. All of Andy's toys except Woody decided to stay at Sunnyside. Lotso at first acts nice to Andy's toys. Woody didn't believe that he should stay at daycare and leaves Sunnyside to go look for Andy, but Woody then gets found by a girl named Bonnie who goes to the daycare, and Woody is taken home to Bonnie's house.

Afterwards, Lotso's true evil character was revealed when Buzz Lightyear was trying to leave the Caterpillar Room. Buzz requests that he and his toys to not be in the Caterpillar Room anymore, but Lotso refuses, saying that the younger children, who don't play nice with the toys as much as Andy did, really need toys. Lotso orders his henchmen toys to switch Buzz Lightyear's play mode to demo mode after Lotso finds the Buzz Lightyear instruction manual, which makes Buzz think that his friends are henchmen of Evil Emperor Zurg, which makes Buzz a hypnotized henchman of Lotso.

Woody during that time meets with Bonnie's toys, Mr. Pricklepants, Peas-in-a-Pod, and others, and when Woody told them that he escaped from Lotso's prison, Sunnyside Daycare Center, all of Bonnie's toys are shocked that Woody actually escaped out of Sunnyside. Chuckles the clown explains to Woody about everything of Lotso's past, revealing that Lotso is a tragic villain, but what he has done was wrong. Woody realizes that he did an incredible action, while he left his friends (when he tried to persuade them to leave Sunnyside).

Meanwhile, the hypnotized Buzz Lightyear locks up Woody's friends in cages and suffer like all the other toys. Woody came back into Sunnyside by going into Bonnie's backpack, but then a chatter telephone toy tells Woody that he shouldn't have come back because now if Woody tries to escape again, then Lotso will know Woody will try to escape. The chatter telephone reveals all of Lotso's security, revealing that a cymbal-crashing monkey toy watches all the security cameras and that the outside is always guarded by truck toys, and his second-in-command Ken (from the Barbie toyline) watches Woody's friends. Woody goes into action while he found Lotso sleeping in a chair.

After Woody rescues his friends by locking up Buzz in a cage, they were about to escape, but then Lotso showed up. However, Woody and his friends explain that all of Lotso's actions are evil, and that Lotso is a bully because he makes other toys suffer from dangerous infant humans play with them. All of Lotso's henchmen, Ken, Big Baby, the monster toys, and others realize this, but Lotso doesn't care and also turns on his henchmen as well. He also snatches the leash name from Big Baby that was given by Daisy and destroys the leash. Big Baby gets angry and throws Lotso into the dumpster. When Woody's friends were about to escape, Lotso pulled Woody into the dumpster.

Soon, Woody, his friends, and Lotso were taken into the trash truck. Lotso begged for help, with Woody and Buzz deciding to help him when he was under a heavy lift object. Woody and his friends told and relied on him to stop the fire that destroys the trash by pushing the stop button. However, Lotso revealed to have tricked them, deciding to let Woody and his friends get destroyed by the fire, and Lotso immediately escapes. However, Woody and his friends were rescued from the fire by a giant claw handled by the three little green men.

Lotso was then found by an old garbage truck driver who tied him to the front of his garbage truck with other toys. Lotso met a cruel fate although still alive.

Trivia

 * Lotso made a cameo appearance in the movie, Up.
 * Prior to the film's release, Pixar created two commercials for Lotso as if he were a real toy, complete with an aged video filter, and uploaded them to Youtube as part of a viral marketing campaign. To increase the effect, the channel featured a few actual old toy commercials as well, leading many to mistakenly believe that Lotso really was an actual toy that had existed before the movie.