The phrase "prowl howl eyes guise" employs alliteration, which is a type of figurative language. Alliteration is characterized by the repetition of the same initial consonant sounds in closely placed words. In this case, the "p" sound in "prowl," the "h" sound in "howl," and the "g" sound in "guise" create a rhythm and a playfulness in the language.
Additionally, the phrase can evoke imagery or suggest a certain mood through the choice of words, which may also be considered a form of imagery. However, the primary figurative language technique at play here is alliteration.