You call forth an aberration, a horror from beyond mortal understanding. An aberration summoned this way has a maximum challenge rating of CR3.
If an aberration summoned by this spell has one or more major eyeball, the eyeballs you used to summon the creature is consumed. You and any aberration summoned by this spell can communicate telepathically as long as you are on the same plane of existence. Aberrations summoned by this spell disappear when they drops to 0 hit points.
The aberration is friendly to you and your companions for the duration. Roll initiative for the aberration, which has its own turns. It obeys any verbal or telepathic commands that you issue to it (no action required by you).
At Higher Levels. When you cast this spell using a spell slot of 5th level the creature's maximum challenge rating becomes CR5. When you use a spell slot of 7th level or higher, the creature's maximum challenge rating becomes CR6. When cast with a 9th level spell slot, you can summon multiple creatures, up to four CR1s, three CR2s, or two CR3 or CR4.
* - (Vial of blood and tissue from a diciest Humanoid.)