Land of Giants and The Giant Claw, marketed together as Chased by Dinosaurs in the United States, are two special episodes of the nature documentary television series Walking with Dinosaurs. Created by Impossible Pictures and produced by the BBC Studios Science Unit, the Discovery Channel and ProSieben, The Giant Claw was first broadcast on 30 December 2002, followed by Land of Giants on 1 January 2003. The two episodes stars British wildlife presenter Nigel Marven as a "time-travelling zoologist", interacting with dinosaurs and other prehistoric creatures, a drastic change in presentation from preceding entries in the Walking with... franchise.

As with previous documentaries in the Walking with... franchise, Land of Giants and The Giant Claw recreated extinct animals through a combination of computer-generated imagery and animatronics, incorporated into live action footage shot at various locations. The choice to include a presenter was made to more easily allow audiences to see the scale of the creatures shown in the episodes. Both episodes have Marven on a purposeful journey; in The Giant Claw, Marven searches for the long-clawed Therizinosaurus and in Land of Giants he searches for the enormous Argentinosaurus and Giganotosaurus.

The visual effects of the episodes were praised, with both episodes together winning the Emmy for Outstanding Animated Programme in 2004 and The Giant Claw winning a BAFTA TV Award for Best Visual Effects in 2003. The success of Land of Giants and The Giant Claw spawned further prehistoric miniseries starring Marven: Sea Monsters (2003) and Prehistoric Park (2006). For his role as the presenter of Land of Giants and Sea Monsters, Marven was nominated for a Royal Television Society Programme award.