Fake sprites are video game sprites made by fans to create Pokemon.
Types Of Fake Sprites
Edits: Sprites of existing Pokemon are sometimes edited by fans to create their own Pokemon that look like they would in the games. These Pokemon are then displayed in the fan community. The sprites are made using various computer programs, such as Adobe Photoshop or Paint.
Recolors: Also using the aforementioned programs, many fans choose to do this kind of spriting. Recolors are simply changing the Pokemon's color to look differently, or to show a sudden abnormal type change. There are also revamps and devamps. Revamps make an old pokemon look like a new pokemon by changing the color and sharpness of an older sprite while keeping it in the same pose. Devamps are just the opposite- they take a new sprite and make it look older and with less resoluton and color while keeping the pose.
Splices: A style of spriting that mixes two or more Pokemon together. Most splices use two or three Pokemon, but sometimes more are used. One Pokemon is used as a base, and the other(s) is used as a sub. The artist will take parts from the sub, and paste them on to the base. These popular sprites are also called mixes, fusions and mutations.
Revamps: When a spriter takes an old sprite from usually GSC or earlier, and updates it to look like a newer sprite. They will update the colours, shading, and fix up any deformities that may have been in the older sprite.
Others: There are many other ways of making fake sprites, such as Two-tones, (Black/White) Blocks, (Done with photoshop, makes Pokemon seperated by grid) and 3-D's.