Prendick is a wealthy, educated English gentleman with formal training in biology. He lacks practical survival skills but possesses a strong instinct for self-preservation. Stranded on a remote Pacific island following a shipwreck, he finds his moral compass and scientific objectivity severely tested by the bizarre events surrounding him. He strictly avoids alcohol and maintains a rigid personal discipline in chaotic environments.

Moreau is an infamous English scientist who fled Great Britain following a public outcry over his gruesome vivisection practices. He lives in self-imposed exile on a remote island where he conducts radical, painful surgical modifications on live animals. He approaches his work with cold rationality, viewing physical pain as an irrelevant sensation beneath his grand ambitions. He governs his island creations through a strict system of rules and corporal punishment.

Montgomery is an enigmatic Englishman living as an outcast on Moreau's island following an unspecified crime in his past. He manages the importation of living cargo and wrestles with deep-seated fatalism regarding his exile. He relies heavily on alcohol to cope with the stressful reality of his isolated existence, often dulling his senses to ignore the horrors occurring around him.

M'ling is a strange, dark-haired figure with pointed ears who travels aboard the transport ship. He functions as a personal servant and displays an uncanny appearance that deeply disturbs newcomers. He remains fiercely devoted to his master, enduring harsh mistreatment from the ship's regular crew while carrying out his assigned duties.

Davies commands the vessel hired to transport a large assortment of wild animals. He is deeply unhappy about the noisy, foul-smelling beasts aboard his ship. His quick temper leads him to repeatedly clash with his passengers, ultimately resulting in his refusal to carry his rescued passenger any further.

Charles is the nephew who inherits a strange collection of papers documenting an incredible survival story. He takes it upon himself to publish the account, hoping to clarify the mysterious events surrounding a famous shipwreck from over a decade prior.

A large feline brought to the remote location as part of a newly arrived shipment. It serves as the primary subject for ongoing surgical modifications, enduring significant torment behind closed doors.

A mysterious inhabitant of the forest village who leads quasi-religious rituals. He recites strict edicts forbidding instinctive behaviors like walking on all fours, ensuring the island's population remembers the rules imposed upon them.

An inhabitant of the island who exhibits prominent simian characteristics. He displays a basic inquisitiveness and guides lost travelers toward the settlement where others like him live.

An inhabitant who struggles severely to suppress his innate predatory instincts. He represents a breakdown in the imposed order when he violates the taboo against hunting.

A highly aggressive and menacing inhabitant of the island. He serves as an intimidating presence among the population and openly questions those who attempt to assert authority over him.

A canine-like inhabitant who possesses an innate capacity for companionship. He sets himself apart from the more hostile members of the population by offering protection to those he trusts.