Shiny Pokémon are special Pokémon that have a different look to normal Pokémon. The only difference is the coloring; shiny Pokémon are not more powerful. Some shinies are a completely different color to normal, while some only have small coloring changes. Shiny Pokémon are extremely rare - every time you encounter a Pokémon there is a 1 in 4096 chance it will be shiny (1/8192 in Generations 1-5). See this Pokébase question for more information.

This is the complete shinydex for Generation 8 (up to Sword/Shield), which shows the shiny version of the 890 Pokémon discovered so far. You can hover your mouse over each sprite (or touch the screen on mobile) to see the normal, non-shiny sprite and compare.

Alternate forms such as Alolan Forms or Mega Pokémon are listed with under generations in which they were introduced.

See also: regular Pokédex or Pokédex with stats