Mosaic--AE

This effect fills a layer with solid color rectangles. It is useful for creating a highly pixelated image.

Horizontal/Vertical Blocks Specifies the number of mosaic divisions in each direction.

Sharp Colors Gives each tile the color of the pixel in its center in the unaffected clip. Otherwise, the tiles are given the average color of the corresponding region in the unaffected clip.

Applying Effects > Video effects included with Premiere > Mosaic--AE