(n.) literally: a snake with a head at each end; a disloyal, two-faced person who usually tries to take advantage of different sides; a Chinese chess tactic
Definitions (粵典–words.hk)
名詞
一個人透過唔同方法討好或者挑撥所有人，從中取利 somebody who works for both sides in a deal; somebody fawn or incite every sides by every possible way for getting greatest interest; literally: two-head snake
近義詞
牆頭草
Definitions (Wiktionary)
noun
bicephalic snake
noun, Cantonese, Hakka, figuratively
double-faced person; someone who behaves differently in front of different people for their own interest