Your connection to the natural world allows you to transform into mightier beasts. 

Once per day, you can expend two uses of Wild Shape to double the CR maximum your Wild Shape allows for. Upon using this effect, Wild Shape uses cannot be regained until after a long rest. This cannot be used to shift into a creature that can cast spells. 

Additionally, when you are hit by an attack you can use your reaction to transform into a beast of CR 1/4 or lower without expending a use of your Wild Shape. This can be done once per day.