Every a week or two, Sam would release a species of shiny (shadow) pokemon available for collection. To collect, you should get a mystery code for that specific pokemon. The code can be derived from the clues given posted in Play Tower Defense Games website blog.
Once you have the code, play the game from Play Tower Defense Games website. Only from this source you can enter the mystery code. Playing any other source would only display the link to the website.
There is an equal chance to get male and female (unless genderless) pokemon. And for limited redeems, a couple is awarded.
When the mystery hunt activity of certain pokemon is over, you cannot get the pokemon using the code.
Note the following pokemons are gifted by making donations:
- Rayquaza: USD $5 or more
- Heatran: USD $10 or more
- Chameleaf: USD $10 or more
- Coalla: USD $10 or more
- Bubbull: USD $10 or more
- Xerneas: USD $20 or more
- Yveltal: USD $20 or more
- Buneary (through Easter egg hunt)