Sirens are a type of mermaid with the ability to hypnotize men. Sirens have all of the same physical characteristics as mermaids such as the tail. Venus is the only known siren. She uses her hypnotic abilities to manipulate men to get what she wants. If a siren's target knows what they are, the siren cannot hypnotize them. Venus' power usually involves mental messages and a glowing, beautiful light around her. When she walks, it seems that she is merely hovering shortly above the ground.
In lore, all mermaids are sirens and use their magical singing voices to lure sailors from their ships and into the ocean, causing them to die. It is unknown if modern sirens use their hypnotic abilities for this.