Note: This page describes a glitch, trick, or exploit. To see others, click here.
If Ammy drowns, succumbs to a Cursed Zone, falls into a void plane, she will respawn at her respawn point. Before control is returned to the player, Ammy goes through a spinning animation and touches down on the ground. If Ammy is above the universal void plane (i.e. there is no collision below her) at any point during her respawn animation, she will gain upwards velocity each frame. This velocity is not applied until the respawn animation ends, at which point Ammy appears to be suddenly flung directly upwards into the air, hence the name Catapult Jump.
After the respawn animation, Ammy will have no initial horizontal momentum, and can only slowly drift in the direction of the analog stick. She transitions directly from the respawn animation to the mid-air falling animation, with no jump, double jump, or chance to D Boost. She only retains her air tackle in terms of movement options. Thus, without the use of the KT Glitch to gain momentum at the peak of the jump, very little horizontal distance can be covered using this glitch, and its applications are limited.
The most common way to perform a Catapult Jump is to perform an Origin Warp on a map where the origin (0, 0, 0) is above the universal void plane, such as the exterior of Oni Island (map r20d), as demonstrated here: https://youtu.be/PoVZ93oka28?t=2990. Because Ammy is already above the void on the first frame of the respawn animation, Ammy will gain the maximum possible upwards velocity, and thus the maximum height.
Catapult Jumps can also be performed without an Origin Warp if Ammy is able to be pushed above the void by nearby collision as she spins around during the respawn animation. This is usually performed by finding a narrow out-of-bounds ledge which is bounded by a wall on one side and a fall into the universal void plane on the other, and inching slowly off of it. Because this is dependent on Ammy's collision moving around during the animation, and the exact collision around her, she won't be gaining upward velocity from the earliest possible frame in the respawn animation, and thus the total height of the Catapult Jump will be reduced by varying degrees.
Catapult Jump was discovered simultaneously with Origin Warp by Raku and demonstrated in this video posted on 08 January 2016: https://youtu.be/935jsU1JsEE, where it occurs after performing OW in Ezofuji.
The earliest known Catapult Jump performed without Origin Warp was done by DriftingPancake (AKA Cerpin/medibisu/zlamp) in this video posted on 25 March 2016: https://www.twitch.tv/videos/56659474, where it occurs after clipping through a wall in Madame Fawn's House using some pots. It was later demonstrated by DriftingPancake via slipping off an out-of-bounds ledge in City Checkpoint on 21 August 2016 in this video: https://www.twitch.tv/videos/85003729.