[3] Walking with Monsters explores life in the Paleozoic era, showcasing the early development of groups such as arthropods, fish, amphibians, reptiles and synapsids.

Like its predecessors, Walking with Monsters employs computer-generated imagery and animatronics, as well as live action footage shot at various locations, to reconstruct prehistoric life and environments.

Walking with Monsters employed the most sophisticated CGI in the entire franchise, featuring 29 different creatures (more than in previous series) in almost 600 VFX shots.

[citation needed] Unlike the creatures featured in previous series, the animals in Walking with Monsters were much less familiar to wider audiences and, according to producer and director Chloe Leland, more "fantastical".

[4] Nathan Southern gave Walking with Monsters a positive review in The New York Times, writing that the programme was likely to "[entertain] young viewers while encouraging them to think about prehistory".

[6] Ian Johns gave Walking with Monsters a negative review in The Times, criticizing its "over-insistence that every creature was locked [...] in a ruthless battle to rule the Earth" and also thought that it had lost the "wow factor" of its predecessors.

A. Gill, also writing for The Times, also reviewed Walking with Monsters negatively, writing that it was full of "small mouthfuls of ghoulish factoids and gory suppositions", that the "monsters look like prototypes for toy manufacturers and computer games" and that the programme seemed to be aimed at "nine-year-old American boys" rather than mature British audiences.