Sprinkler

The Sprinkler is a sub weapon in Splatoon and Splatoon 2.

The Sprinkler continually sprays Ink in a circular ring around itself, in a staggering motion, until it is broken by enemy fire or it once the player who placed it gets splatted. It can be thrown onto virtually any surface, including ones that are upside-down. If the user throws another sprinkler with one already in use, the first one will automatically break. Sprinklers will have an infinite duration unless they are destroyed, replaced, or the owner of said sprinkler is splatted.

Splatoon
"This device functions just like a lawn sprinkler, spreading ink over a modest 360-degree radius. The narrow streams of ink don’t inflict much damage, but Sprinklers are a good way to maintain ink coverage in high-traffic areas during both Turf War and Splat Zones. Instead of tossing it on the ground, where it’s likely to be spotted and destroyed, consider throwing it high on a wall—it will stick to any surface, like a Suction Bomb. But you can only deploy one Sprinkler at a time. If you toss a second one out, the first one will disappear. Enemy Sprinklers can be destroyed by shooting them. If left untouched, a Sprinkler will continue spreading ink indefinitely."

- Splatoon Prima Guide

Splatoon 2
The Sprinkler was tweaked in Splatoon 2 to have its inking power start out stronger but weaken over time. There are four distinct phases:
 * Deployment phase: This phase starts when the Sprinkler lands on the ground and ends when the Sprinkler fires its first drop of ink. This phase lasts one second.
 * High-power phase: The Sprinkler spins the fastest and has the most inking power during this phase. It lasts 5.33 seconds.
 * Mid-power phase: The Sprinkler slows down and inks less in this phase. It lasts 16 seconds.
 * Low-power phase: The Sprinkler slows down even further, with very low ink output and range. This phase lasts for the remaining lifetime of the Sprinkler.

Tips

 * The most effective spots for Sprinklers are those that are hard to see or reach. These include on top of boxes, sideways on walls, or on objects over the stage.
 * Exploring stages in Recon mode makes it easy to find strategic locations for Sprinklers without the pressure of a battle.
 * Putting a Sprinkler directly at one's feet can allow a chance to react should an enemy launch a sneak attack.
 * Sprinklers placed on or near the tower in Tower Control can provide some cover for the user and their allies.
 * Like Squid Beakons, Sprinklers can be used as light shields in a pinch, taking some damage in place of the user.
 * Also like Beakons, Sprinklers work as bait to attract players and abush them while reaching to destroy the sprinkler.
 * Even when not used as shields, the attention drawn by an unguarded Sprinkler can be used to one's advantage for an ambush or escape.

Countering

 * One should avoid getting too close to enemy Sprinklers - while their damage is low, multiple hits can be dangerous.
 * A Sprinkler may be bait, especially if stuck to a high wall or ceiling. It would be wise to keep an eye on one's surroundings when destroying it.

Trivia

 * Sprinklers spin much faster in Splatoon 2.
 * The logo can be found on the lower part of the Sprinkler
 * Marie calls throwing a Sprinkler in the last few seconds of a battle in order to gain a bit more turf Last Seconds of Summer.
 * In Splatoon 2, there are no rollers or chargers that have Sprinkler as their sub weapon.