Original Post

<aside> 🌷

Proto Piranhas, originally known as Gatekeepers and also known as Proto Piranha Plants, are large Piranha Plants made entirely of goop. In this blog post, the Gelato Beach Proto Piranha is referred to as a “Mud Piranha”

</aside>

About a year and a half ago, an idea was proposed to defeat the Mud Piranha on Gelato Beach while collecting the Shine on the beach. Although it wasn't the first time someone had come up with it, no one had seriously considered using the idea because of risks like soft-locking the game and the frequent issue of attacks not hitting the Mud Piranha.

However, in a video demonstrating the idea, methods were shown that avoided these problems and made the strategy viable for RTA (real-time attack) runs by reducing the difficulty to a reasonable level. These methods were:

• Keep the Mud Piranha off-screen
• Be careful because delivering the final blow will forcibly cancel jumps and hover boosts

After this method was introduced, runners who combined this with collecting the beach Shine started to appear in RTAs. However, the reason why attacks wouldn’t connect when the Mud Piranha was visible on-screen remained unknown.

I had also been thinking about investigating this myself, but I was too busy with the 120 Shine TAS and lacked the motivation to start the research. Then in 2020, a runner asked me why the attacks would connect when the Mud Piranha was off-screen, which finally pushed me to investigate. I discovered the cause and am now reporting the results.

The original idea can be found in this tweet:

“It’s unclear whether this makes things faster, but in terms of difficulty, it’s usable even in 120 and 96 (Shine categories).

Points to Note:

• Do not let the camera show the moment the water hits the Mud Piranha
• If the 6th water spray hits during a hover or while rising in a jump, the hover or upward movement will be canceled”

https://twitter.com/Nanashi_745/status/1045648660082483201

Investigation Process

I’ll leave a record of how I carried out the investigation this time, for reference.

First, I identified the memory address that manages whether or not the Mud Piranha (どろパックン) is on-screen. The investigation can be done without it, but I felt having it made things easier.

I began testing by attacking the Mud Piranha from the pillar, just as in RTA runs, and first tried spraying water while it was on-screen. The result: the water didn’t hit—it seemed to be out of range. Then, following the original idea, I moved it off-screen and tried again without changing the shooting angle, and this time the attack connected. This confirmed that attacks land when the Mud Piranha is off-screen.

Next, I tried forcing the value from the earlier memory address to make the game think the Mud Piranha was off-screen. However, this had no effect. It seems that the game’s internal logic takes priority over externally modified values.

After that, I changed the camera coordinates to focus on the Mud Piranha’s area, but once again, when it was visible on-screen, attacks didn’t land. However, when I quickly moved the camera right before the water hit, I managed to capture the moment of the attack connecting. This led me to the theory that when the Mud Piranha is off-screen, its damage hitbox expands beyond just the mouth.