Tröma Nakmo (Skt. Krodhakālī; Tib. ཁྲོས་མ་ནག་མོ་, Wyl. khros ma nag mo) — the Black Wrathful Lady, a form of Vajravarahi.
A famous practice of Tröma Nakmo was revealed by Nyang Ral Nyima Özer. In more recent times, Dudjom Lingpa has also revealed a practice of Tröma Nakmo which has become very popular.