'anthropomorphiser' originates from modern English, formed by adding the agentive suffix '-er' to the verb 'anthropomorphize'. 'anthropomorphize' itself ultimately derives from Greek elements: 'anthropos' meaning 'human' and 'morphē' meaning 'form'.

'anthropomorphiser' developed from the late 18th–19th century verb 'anthropomorphize' and the noun 'anthropomorphism' (from New Latin/Greek roots). The agent noun was formed in English by attaching '-er' to denote a person who performs the action.

Initially the roots referred literally to 'human form' ('anthropos' + 'morphē'), but over time the verb and derived nouns came to mean 'to attribute human traits or form to non-human entities', which is the current sense.