Circle Forms

2nd-Level Druid, Circle of the Winter Pheonix Feature

The rites of your circle grant you the ability to transform into more dangerous animal forms. Starting at 2nd level, you can use your Wild Shape or Animalistic Adaptation to transform into a beast with a challenge rating as high as 1 (you ignore the Max. CR column of the beast shapes table, but must abide by the other limitations there).
Starting at 6th level, you can transform into a beast with a challenge rating as high as your druid level divided by 3, rounded down.