"Creature" was a term which described an animal or a sentient individual.
In his commencement address at Princeton in 2063, Zefram Cochrane called the Borg "cybernetic creatures from the future." (ENT: "Regeneration")
Sub-Commander T'Pol once suggested that Phlox could place his creatures together in their cages but Phlox told her they would eat each other. (ENT: "The Catwalk")
Doctor Phlox later also used the word "creature" to describe what he didn't wish to turn into following his assimilation. (ENT: "Regeneration")
The Talosian Magistrate referred to Captain Christopher Pike as a "creature" in a conversation with other Talosians. (TOS: "The Cage")
The Horta of Janus VI was referred to as a "creature." (TOS: "The Devil in the Dark")
The Bajoran mythology called the Dal'Rok a "mythical energy creature". (DS9: "The Storyteller")