If you turn off the light in Poniko's House, there is a 1 in 64 chance that the Uboa event will occur. Whether the event will occur is determined when the player enters the room (leave and enter again for the next chance) or waits five seconds after trying. Uboa was added along with the Pink Sea and KyuuKyuu-kun in version 0.08.
Uboa appears as a black blob or shadow-like creature with a white oval covering most of its front, giving it a monochromatic look. The oval resembles the traditional Noh theatre masks, as well as the Greek comedy/tragedy masks that depict extreme joy or sadness. However, in regards to the Greek masks, Uboa's expression seems to be a blend of both, as its left eye is squinting, while its right eye is resting. Accordingly, the left corner of the mouth is turned up, while the right corner is turned down. In the right upper part of the oval, the black color invades it slightly, making the "mask" appear "cracked". Uboa also appears with a warped expression after the player interacts with it (see below).
There is a chance that the event is triggered when you turn off the light. 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 (also played in Guillotine World). You cannot leave the room, and flipping the light switch only causes another flash.
Some of the items in the room change. The dresser gets a "face" with googly eyes that are similar to those of Masada's and a smile. The two pictures change, the one over the desk turns from what looks like a mouse to a face which has googly eyes as well, and what could be either a moustache or another smile. The one over Poniko's bed changes from one shape to another. The window gets eyes and the rug's design also changes, showing a pattern with eyes as well. The lamp on the desk turns on, showing a light beam.
If you interact with Uboa, its face will become warped and you will be sent to a sectioned off part of the White Desert known as Uboa's Trap, without a way to get back. The area shows a monochrome background with a few hills and a large decorative NPC that is groping them. There appears to be fluid on these hills, similar to landscapes seen in the White Desert.
When walking, Madotsuki's footsteps make the same "water" sound effects also heard when adventuring through the Pink Sea, so the white, wavy ground can be interpreted as the same sort of substance.
Using the Frog effect here will increase Madotsuki's movement speed as well. Uboa itself is seen motionless with a rather warped expression near the middle of the map. It is impossible to interact with them. The only way to escape this area is by pinching Madotsuki awake or by using the Medamaude effect.
Sound associated with Uboa.
|The background music that plays when Uboa is in Poniko's House.|
|The White Desert soundtrack that plays after you get teleported to the new area.|
Uboa is likely a major factor for the success of the game, especially in the English version. Many non-Japanese players were introduced to Uboa through YouTube. Uboa itself may very well be the number one inspiration to download and explore Yume Nikki by most fans.
Isolation - Due to being trapped after making Madotsuki interact with Uboa, and the following area playing the dreary White Desert soundtrack, it could relate to the game's recurring theme of isolation.
Poniko's True Form - A common interpretation is that Uboa is Poniko's true form, mostly because they replace her sprite.
Revenge - Uboa could be an annoyed Poniko getting angry with Madotsuki, as she keeps switching the lights off and on, which could be seen as a prank.
- The sound effect that plays when the player touches it is the same one as when a Toriningen traps the player.
- It is one of four characters in the game that cannot be killed, along with the Jellyfish, Toriningen, and Pain Blob.
- Uboa and the Jellyfish are the only ones who have no reaction to the Knife effect at all.
- This is lost in English, but the syllables that make up Uboa's name (ウボァ) do not normally go together in Japanese, with the effect of the name being similar to Cthulhu or Astfgl in its "wrongness".
- Both the Alley Demon and Pier Monsters share a vague resemblance to Uboa.
- Uboa is one of the most popular characters from the game and has made cameos or was inspiration for other characters in fangames and other (indie) video games.
- Yume 2kki - In the Sky Kingdom world there is a dog-like character that resembles Uboa. This character has been called "Dogboa" by fans. Additionally, in the Extraterrestrial Cliffside and GB Fields areas, there are parts of the ground which resemble Uboa, and a similar event was found in previous versions of the game.
- .flow - Uboa makes a cameo as a marking in the dead end room in the Underwater Temple.
- Me - the Mask effect is a clear reference to Uboa's face, and the location it's found in is quite similar to Poniko's room. Earlier versions of the game featured a similar event.
- Undertale - W. D. Gaster (Or, more accurately, the Mystery Man) bears a striking resemblance to Uboa, and they both have a low chance of being seen by the player without them knowing about it. The creator has referred to Uboa in other works as well.
- Imscared - White Face shares some similarity to Uboa, notably due to looking like a "cracked" mask (Although White Face's seems to be more akin to a tear).
- LISA the Joyful - Mr. Beautiful has a mask that appears similar to Uboa once cracked in battle. However, Dingaling, the game's creator, stated on Twitter that the similarities weren't intentional, and that the character was instead based on Shoko Asahara.
- Nightmare House 2 - Uboa appears as a hidden easter egg.
- BoxxyQuest: The Gathering Storm - A creature resembling Uboa appears in an abandoned shack. Also, a full recreation of Poniko's house and the Trap World can be found in the game's unused code, possibly intended as an easter egg.
- According to some, Uboa's design (that of its initial sprite) was likely inspired by No-Face from the Japanese film Spirited Away.
- No-Face is in turn inspired by Noh theatre and could also be based on the kōken, the stagehands dressing in all black, moving the scenery and props.
- Uboa's name originated from a type of scream in Japan. Originally pronounced 'uhoa' (ooo-hwha) when said in a manner resembling a scream, the name certainly suits its appearance and situation.
- The scream was popularized by Emperor Mateus from Final Fantasy II, who screamed Uboa when he was defeated in the NES/FC Japanese version and English prototype. This was likely part of the inspiration for the name.
- The origin of Uboa's face design prior to its distortion when the player touches it may have come from a 1997 Treasure game called Mischief Makers. This may be coincidental however. In Mischief Makers, the denizens of the planet Clancer as well as most objects on the planet all have black, hollow-looking eyes similar to Uboa's that may be both curved inward or one curving outward. These creatures also possess gaping black mouths and white faces, much like Uboa.
- In the walfas' create.swf (despite being Touhou in origin but because of Uboa's meme status) Uboa's face is an option to use on a character.
- Uboa makes a cameo appearance in the Abyss location of the webcomic Awful Hospital.