Chunk

Chunk is one of the supporting antagonists in Toy Story 3 but in the end he reformed.

Toy Story 3
Chunk is a rock-like toy from Sunnyside Daycare. Chunk has protective shoulder spikes, poseable oversized limbs, and fists ready to smash anyone who gets in his way. He also has a hidden head spike which when pressed down on switches Chunk's facial expression from friendly to fierce. He starts out as one of Lotso's henchmen, but in the end is reformed.

In the end credits, when Sunnyside is turned from a prison into a paradise by Barbie and Ken (who are now the new leaders of Sunnyside after Lotso's defeat), he is shown experiencing a rough playtime with the toddlers in the Caterpillar Room, being hammered to the floor and thrown across the room. After landing back under a shelf, where Twitch is waiting for his turn, Chunk tags Twitch so Twitch can substitute for Chunk while Chunk rests under the shelf with Ken and Barbie. When the Sunnyside toys have a "beach party" at the sandbox, Chunk is shown playing beach volleyball with Jack-in-the-Box as they bounce a ball back and forth between each other's teams.

Toy Description
From Official Website:

"Chunk will rock your world! This gargantuan creature sports protective shoulder spikes, while his ferocious fists are ready to smash whatever enemy gets in his way. Chunk's oversized limbs are fully posable, making him ready for hours of imaginative fun. As an added bonus, the press of a hidden head spike will spin Chunk's expression from friendly to fierce! No batteries necessary."

Trivia

 * Chunk appears to be based on the short-lived Rock Lords toyline from the 1980s.
 * Many of the Chunk toys created have the face feature. However, some have it changed by pressing the spike on the top (as seen in the picture below toy description), and the others have it changed by swiveling his face.