Elemental Evolution

After spending the casting time tracing magical pathways within a precious gemstone, you touch a Gargantuan or smaller beast or monstrosity. The target's creature type become elemental and also gains the ability to understand Primordial. Your GM chooses statistics and traits appropriate for the evolved beast or monstrosity, typically getting a higher AC or more powerful natural weapons.

The evolved beast or monstrosity is charmed by you for 30 days or until you or your companions do anything harmful to it. When the charmed condition ends, the evolved creature chooses whether to remain friendly to you, based on how you treated it while it was charmed.