biàn​tài

abnormal

变态 (變態) biàn​tài
abnormal noun
psychologically abnormal, perverted, or deviating from a normal state

This kind of abnormal psychology often stems from childhood trauma.

metamorphose verb
to undergo biological metamorphosis or transformation of form

A silkworm undergoes several metamorphoses before turning into a moth.

pervert verb
a person who is sexually deviant; a pervert or hentai (often used as an insult)

Get away from me, you pervert!

Frequency

Movie subtitles
40.5 per million appears in 14% of films
Written text
15.3 per million

Sources

Definitions
CC-CEDICT