Sphynx Clip

Sphynx Clip is a cap throw clip in the Sand Kingdom that allows the player to clip through the wall just behind the Sphynx at the backside of Tostarena Ruins. Clipping through this wall not only enables Mario to enter the treasure vault without talking to the Sphynx, but it also allows the player to access the room containing the Hidden Room in the Flowing Sands moon without the need to sink into the quicksand. Like all cap throw clips, Sphynx Clip can only be performed on game versions 1.1.0 and earlier.

This glitch was formerly used in the Any% category to save up to 10 seconds. However, since version 1.3.0 has significantly faster loading times than all previous versions of the game, the time saved by Sphynx Clip and other version-exclusive tricks has since been negated. Additionally, with the introduction of Daylight Savings Time Abuse as well as Platform Clip and Icicle Clip, it is unknown whether the use of Sphynx Clip is still optimal for older versions.

Execution

Performing Sphynx Clip utilizes the same button inputs as a roll cancel clip (despite not technically being one). The setup used is as follows:

Position Mario on top of the highest flat surface on the Sphynx's back, at the very left edge, so that he is partially visible from behind the Sphynx's head. Setups vary, but many players prefer a position where Mario is standing halfway on top of this surface.
Face Mario directly toward the wall behind the Sphynx (south).
Press the crouch button and crouch-walk forward for a couple of steps to ensure that Mario is the optimal distance from the wall.
Instead of performing a regular jump to initiate the ground pound, perform a backflip and then immediately ground pound.
After the ground pound lands, perform the standard roll cancel clip inputs (Y+X+B or any equivalent sequence of inputs). If attempting to clip without entering the loading zone, hold the joystick to the left during these inputs.

Variants

There are two variants of Sphynx Clip that appear in Any% speedruns: single clip and double clip. Both variants utilize the clip not only to access the vault room and collect the Sphynx's Treasure Vault moon, but also to collect the Hidden Room in the Flowing Sands moon as well.

Single clip

Single clip, as the name implies, only relies on using the clip once to collect both moons. While clipping, the player must hold the control stick to the left so that Mario does not yet activate the loading zone to the treasure vault room, instead opting to collect Hidden Room in the Flowing Sands first. While collecting this moon, the player must remain partially out of bounds, so that afterwards they can dive back toward the loading zone and collect the moon from inside the treasure vault room. Upon exiting the vault room, the player can simply make their way over to the area with the Bullet Bills while remaining in bounds. This variant saves about seven seconds over the normal route.

Double clip

Double clip utilizes the clip twice to eliminate the need to backtrack, saving an additional three seconds over single clip and resulting in a total time save of around 10 seconds. The first clip is used to enter the loading zone immediately. After exiting the vault room, the clip is performed again in a manner identical to that of single clip, bypassing the loading zone and collecting Hidden Room in the Flowing Sands while partially out of bounds. Afterwards, the player can continue to travel toward the area with the Bullet Bills while remaining out of bounds.