Ruby
A Ruby is a legendary item which can be used to summon a Groudon egg.
How to obtain it
You can obtain a Ruby if a Fire or Ground Type Pokemon wins the Groudon boss battle in the Terra Cave rumble area.
How to use it
Using the Ruby, you are able to summon a Groudon egg in the Ancient Cave.
Other
- Rubys are trade able.
- Hatching a Groudon egg will count towards your shiny chain.