Mario Decal

The Mario Decal is the name given to a texture of the original Super Mario Bros. jumping sprite found in the files of Super Mario 64. In retail copies, it has no function or purpose, leaving it as a typical unused texture. However, it may be used by the Personalization A.I for a variety of purposes, usually as a form of debugging or placeholder texture.

Debug Appearances
Most commonly, the Mario Decal is reported to appear in what is believed to be a variety of debugging features and methods. In most reports, it simply appears as a graphic as a part of an also anomalous Debugging menu, although it may also be used to signify certain information (i.e. appearing when Mario is considered airborne).

Some have also reported it appearing briefly when booting up the game, most commonly on the Title Screen, before disappearing. What purpose it serves is unknown.

Texture Re-Arrangement
In some reports, the Mario Decal can appear in-game as a standard texture used by the A.I. It most commonly simply appears overlayed over a wall, hence the name "Mario Decal", and it may hint towards the location of a collectible such as a Power Star or Anomalous Collectible.

It may also appear as part of custom-made geometry. A common manifestation of this effect is appearing as a photograph of Mario found in the anomalous Princess Peach's Bedroom, however it has been reported in a large number of anomalous areas.

A.I Dementia Decal Corruption
Main article: A.I Dementia

An uncommon effect of A.I Dementia results from the Mario Decal being seemingly entirely unaffected by the anomaly. Even through large data erosion, the Mario Decal is known to persist. If it has already been used in one of the above conditions by the A.I, the Mario Decal may begin to appear in more places, over-riding over textures. This is referred to as "Decal Corruption".

As the A.I Dementia worsens, the Mario Decal will overwrite more and more textures, usually lasting until the game crashes due to the dementia. Through data mining, it is learned that the A.I makes thousands of copies of the Mario Decal texture, most often including replacing several if not all other texture files. There seems to be no hard limit on how many copies of the Decal the A.I can make, and it is believed that it would theoretically be able to replace the entire base game with copies of the texture should it somehow be able to avoid a crash.

The Mario Decal is also reported to commonly appear in copies that later undergo A.I Dementia, although due to the various conditions that can spawn the Decal, whether the two are correlated is unknown.