Freerunning is an alternative cost, not an activated ability or anything, so you can cast creature spells for their freerunning cost with Caverns colored, uncounterable mana
Befriend Them Create two 1/1 red Goblin creature tokens
Costing five mana to play, with additional investments of mana, Skithiryx is capable of regenerating itself as well as giving itself haste
RITH, LIBERATED PRIMEVAL Rith, daughter of Palladia-Mors, was one of the five ancient Primeval Dragons who ruled Dominaria sometime after the Elder Dragon War
This one has the Shiny artwork seen in sets like Shining Fates and Hidden Fates
For example, a creature with protection from blue cannot be blocked by blue creatures, dealt damage by blue creatures, or enchanted, damaged, or otherwise affected by blue cards