Cavewalker

Mountainwalk
When Cavewalker deals combat damage to a player, if that player controls a Mountain, create a colorless Gold artifact token with "{t}, Sacrifice this artifact: Add one mana of any color to your mana pool."
"Robots like these are easy to build, can have a great purpose, and help me find treasures in the great mountains" - Yadra the Treasureseeker