Andy Serkis played Gollum using motion-capture performance in The Lord of the Rings film trilogy.
Gollum is the corrupted former Ring-bearer who has possessed the One Ring for centuries. Serkis supplied the character’s voice, movement, and performance, while visual-effects artists created Gollum’s digital appearance. His work helped establish motion capture as a major tool for dramatic character acting in large-scale films.
Gollum’s split personality is reflected in the names Sméagol and Gollum. Sméagol is the earlier identity of the Hobbit-like creature, while Gollum represents the personality shaped by isolation and the Ring’s influence. His knowledge of Mordor makes him valuable to Frodo and Sam, but his desire for the Ring makes him deeply dangerous.
Serkis did not physically appear as Gollum in the same way he played a conventional live-action role. That distinction is why the performance is often described as motion capture or performance capture rather than simply a makeup performance.