Siren Monokuma generally resembles the original Monokuma, but it has several noticeable differences. Its left side has black and yellow stripes, its teeth are silver instead of white, and its belly button is a yellow triangle with a red exclamation mark in the middle. The Siren Monokuma also has a red siren on its head and a large metal backpack placed on it's back.
If a Siren Monokuma sees Komaru, it lets out a violently loud wail from the siren on its head, alerting surrounding Monokuma Units. As such, Siren Monokumas should be defeated quickly and stealthily before they can alert their allies.
Additionally, the Siren Monokuma has a unique reaction to the Dance Truth Bullet - when affected, its siren begins flashing rainbow-colored symbols as it dances. This attracts nearby Monokuma Units without making them hostile to Komaru, allowing her to clear them out or sneak past them more easily.