Normal-type Pokémon Zangoose is rare to find in and it is even harder to find a Shiny version of it. Shiny Pokémon have appeared across the series in numerous games, and trainers have always been keen to track down every unique version they can.
However, Shiny Pokémon like Mega Heracross have a much lower spawn rate than normal versions, making it very rare that you will come across one.
Thankfully, during special events, you have a better chance of finding Zangoose and an opportunity to catch a Shiny version.
Currently, Rivals Week 2024 is taking place in and one of the featured Pokémon during the event is Zangoose, making him much more likely to appear in the wild, as well as in raids and from research tasks.
Ditto is one of the most unique and hard Pokémon to find in Pokémon GO, disguising itself as eleven different alternate Pokémon in May 2024.