Poniko is a character from Yume Nikki. She is a girl who appears in one of Madotsuki's dreams. Her house is found in The Pink Sea, which is accessed by diving into a pool located in an igloo in the Snow World. She lives alone in a single room, like Madotsuki herself. She may prefer solitude, as she is located in one of the deeper dream locations and is the only NPC present in The Pink Sea. She appears as a Stage Hazard in All Star Smashers, appearing in Yume Nikki 3D. When summoned, she just stands stationary in one spot on the stage, replacing the stage's music with her theme from Yume Nikki. Then, the lights dim as she transforms into Uboa, who replaces the stage's soundtrack with it's horrible scream. If nobody touches it after 12 seconds, it disappears. However, the poor soul that DOES touch it will receive damage and will get temporarily paralyzed.
If you turn off the light in Poniko's Room, there is a 1 in 64 chance that the Uboa Event will occur. When the event happens a bright flash fills the screen, then the entire room changes and Uboa replaces Poniko. The background music changes to an alarming filtered "aah" noise. If you interact with Uboa, it's face will become warped and you will be sent to a looped area highly similar to the White Desert.
Aside from being a Stage Hazard in All Star Smashers, Poniko is also an Assist Trophy in Smash Bros Lawl.