Sméagol’s later name in J.R.R. Tolkien’s legendarium is Gollum.
Sméagol was a river-dwelling hobbit-like figure who discovered the One Ring while fishing with his relative Déagol. He murdered Déagol to obtain the Ring, and its corrupting influence eventually drove him into isolation beneath the Misty Mountains. His habitual choking sound led others to call him Gollum.
Gollum is central to both The Hobbit and The Lord of the Rings. He once possessed the Ring for centuries before losing it to Bilbo Baggins. The name Sméagol therefore refers to the character’s earlier identity, while Gollum reflects the transformed creature readers encounter in the main story.