The only way to secure one is repeatedly catching the normal spawns of those on the Pokemon GO Ditto disguise list and hoping for the best. Shiny Ditto has a 1 in 64 chance of appearing.

Ditto - also known as the transform Pokémon - is one of the more elusive creatures in Pokémon Go, thanks to its ability to disguise itself as other creatures. In the main games, this purple blob ...