Damage Boost
Explanation
When Ammy runs into certain obstacles, or gets hit by certain NPC's, she experiences a damage/recoil animation which leaves her rear paws on the ground and stops her in-place. She can experience this same animation on the ground or in the air. If the animation ends while she is still in the air, there is a single frame at the end where a jump or tackle can be input, which will behave as though Ammy were grounded. This is similar in nature to the aerial KT Glitch, but works on every version of the game.. This can be chained together as long as Ammy can collide with the damage source.
In order to actually gain height this way, Ammy needs to be damaged at the very start of a ground, double, or wall jump, so that the damage animation finishes by the peak of her jump arc.
Unfortunately, there are no known practical uses for this trick, due to the heavy limitation of requiring a tall damaging surface to gain significant height. However, it can be used to get out-of-bounds in the very starting area of the game, before even entering the River of the Heavens.
In theory, it is possible to use this technique to save yourself if you get hit by falling acid while escaping from the Water Dragon, by mashing tackle as soon as you get hit to hopefully nail the Damage Boost frame, but this would be an extremely rare event.
Demonstration: https://youtu.be/XauIMp9UMMM