The Rivulet

Rivulet is one of nine playable slugcats in Rain World, and is one of the six added in the DLC Downpour. Created by an unknown entity, they are an aquatic slugcat who is able to quickly traverse the flooded world. By the request of the dying Iterator Five Pebbles, they take his Rarefaction Cell and bring it to his neighbor Looks to the Moon, restoring some power to her facility.
== Appearance ==
Rivulet is a light blue slugcat with a small black nose. They have large, round magenta eyes with wide black pupils, and three pairs of magenta frills on either side of their head.
== Biography ==
Chronologically, Rivulet's campaign takes place between Monk and Saint.
Rivulet was created by an unknown entity, likely an Iterator, and end up in the section of the world inhabited by two other Iterators known as Five Pebbles and Looks to the Moon, which has been flooding far more than usual thanks to the former's attempts to flush a disease called the Rot out of his can.
As Rivulet traverses the world, they come across Five Pebbles' mostly destroyed superstructure, and find there way into his chamber. There, he tells them he's seen their kind many times before, paying little attention to most of them beyond giving them a mark of communication and directions to the Depths. He tells the blue slugcat that he doesn't have anything for them, lamenting that he can't help them or himself. He then remarks that slugcats are resilient creatures for so many to have made it to his chamber, especially in his current state.
Pebbles then informs Rivulet that he has no gift for their achievement, and cannot be saved or forgiven for what he's done. He then informs them of a Rarefaction Cell in his Linear Systems Rail that acts as a backup power generator for Iterators, asking the frilled creature to take it and bring it to Looks to the Moon. He adds that once the Cell is gone, his systems will start to shut down, and he'll slowly die, stating that he can't run from his mistakes forever and has already made his choice. If Rivulet grabs the pearl playing music on his chamber's floor, he'll explain to them that it's a hymn from the long-gone inhabitants of his city that he plays to pass the time and bring himself a bit of comfort.
Once reaching Looks to the Moon to the far east, she greets Rivulet and says it's been a long time since a slugcat has visited her, noting their unique aquatic adaptations. She then wonders who gave them a mark of communication, since Pebbles is in no state to do so, asking if they've met fellow Iterators such as No Significant Harassment or Chasing Wind. She then comments on how the frequent rainfall has begun to slow, wondering if Pebbles had finally collapsed and hoping that he instead had found a way to ascend. She remarks that she's not sure how many functional Iterators are left, and that a new cycle is unfolding that they don't need to be apart of, as they've already served their purpose long ago. She then says that as long as she's still functioning, she'll be there as someone to talk to.
When presented with the Rarefaction Cell, she explains that they serve as a backup power supply created when the Iterators' creators, the Ancients, had left and were no longer able to maintain them. She concludes that Rivulet having one can only mean bad things for its original owner, and hopes the slugcat hadn't been the one to remove it, as she has experience with losing Cells, with all of hers being washed away following her collapse. She says the Cell would be invaluable to her, but the lower half of her facility is submerged underwater, making it dangerous to try and install. She tells them there's an access shaft into the lower facility if they want to try, warning them to be careful, as she isn't sure how much of it is left.
Rivulet then enters the Submerged Superstructure, finding The Heart and inserting the Cell into it. The Heart then fills with water, and the blue slugcat is swept the a strong current into Bitter Aerie, where they must head west to return to Moon. Once they get back, Moon says she feels like she's just woken up from a deep sleep, asking Rivulet if they're responsible. She looks through all the messages and Overseer recordings she wasn't able to view, shocked by just how much she'd missed, one message reminding her of No Significant Harassment sending Hunter to save her with slag reset keys. She then states she doesn't understand all that's happened, wondering if other iterators had sent help in the past as well.
She then worries for Five pebbles, as the last time she had been in contact with him was when he was ill with Rot, and has only gotten much worse over time. Moon reminisces on when the two of them were good friends, and worries that he's probably alone and frightened now. She reads a message from him about no longer being able to run from his mistakes and asks what he had done. She states that it doesn't matter what happened between them, as if he was still angry with her, he wouldn't have sacrificed the last of his power to her. She says he deserves to know his efforts weren't in vain, and expresses how grateful she is for his decision, starting a privet broadcast between the two, and asking him to respond if he had received it.
Should Rivulet reach Karma 10, the Guardians will allow them into the Depths, where they can reach the Void Sea and ascend. However, this ending doesn't show what happens to them, only showing a closeup of their face.
== Gameplay ==
Rivulet is unlocked alongside Spearmaster after beating Hunter's, Artificer's or Gourmand's campaigns.
Rivulet is incredibly fast both on land and in water, and their jump and backflip are quite high, as well as their slide covering a sizable distance. Enemies are unable to grab Rivulet while they're running at full speed. They have a much better lung capacity than all other slugcats, allowing them to stay underwater for much longer, and they are able to eat underwater as well. They can boost themself while swimming, though this causes their air to deplete faster. Their throwing distance, spear damage and stealth are all average.
To hibernate, they need to fill up five food pips, with one extra pip able to be carried into the next cycle. They begin the game in Drainage System with a mark of communication and a celadon pearl stored in their stomach. Their campaign opens with two explosions being heard from off screen, before they and a dead scavenger fall into the water.
Cycles are far shorter than normal, lasting a minimum of two and a half minutes before the Rain comes. Due to this, the player should avoid fighting whenever able, and focus on filling their food pips and locating the next shelter as they progressively make their way towards their destination. Shelters will also fail and flood with water more often than usual, being unusable in the following cycle. Non-lethal precycle rain will also pour for a few minutes before the cycle properly begins, allowing a little more time before the next Rain.
Due to the massive increase of water, aquatic creatures such as Eel Lizards and Aquapedes are more common. The water of Shoreline and Garbage Wastes is now a clean blue, and part of the western end of Subterranian has collapsed, rending the Outer Expanse inaccessible. Five Pebbles' can has been completely overtaken by Rot, now being renamed The Rot, being partially flooded and infested with Brother and Mother Long Legs. The Rot has spread down to The Exterior as well, and into part Memory Crypts, the latter because of peices of Underhang falling into it. Miros Birds are no longer present in Memory Crypts, among several other miscellaneous changes around the world.
After obtaining the Rarefaction Cell, Rivulet is considerably slower while carrying it. When holding the pickup button while carrying it though, gravity around Rivulet will decrease for fifteen seconds, allowing the slugcat to swim faster and jump higher, having a ten second cooldown after. The chances of a shelter failure also decrease considerably after getting the Cell.
Beating their campaign will earn the achievement An Old Friend, and beating Spearmaster's as well unlocks Saint.
== Gallery ==
File:RivuletTitleCard.png|Rivulet's title card
File:RivuletHibernation.png|Rivulet hibernating
File:RivuletRarefactionCell.png|Menu art while in possession of the Rarefaction Cell
File:RivuletOldFriendEnding.png|Menu art after the An Old Friend ending
File:RivuletAscension.png|Rivulet ascending
File:RivuletAscentionEnding.png|Menu art after the ascension ending
== Trivia ==
* Rivulet's frills are based off of that of an axolotl's.
* They are the only slugcat to have irises, though they aren't visible in-game.
* Moon has seven neurons in their campaign compared to her usual five, implying Monk may have given her two more at some point.
* While not having a gender in canon, Rivulet is referred to interchangeably as she/her and they/them in the non-canon dating sim.
== External links ==
Rivulet on the Rain World Wiki
Category:Video Game Heroes
Category:Indie/Doujin Heroes
Category:Genderless
Category:Animals
Category:Bio-Engineered
Category:Creations
Category:Mute
Category:Predators
Category:Fighters
Category:Lethal
Category:Chaotic Good
Category:Determinators
Category:Successful
Category:Status Dependent upon Player Choice