Conjure Aberration

You summon an Aberration that has a challenge rating equal or lower to your character Level, which appears in an unoccupied space that you can see within range. The Aberration disappears when it drops to 0 hit points.

The Aberration is friendly to you and your companions. Roll initiative for the Aberration which has its own turns. It obeys any verbal commands that you issue to it (no action required by you), as long as they don't violate its alignment. If you don't issue any commands to the Aberration, it defends itself from hostile creatures but otherwise takes no actions.

You cannot summon an aberration with legendary actions or lair actions, you can't summon an aberration bigger than large.

At Level 20. at level 20 you can summon 1 aberration with legendary action.