Summon Fiend: Casting Time: 1 action Range: 90 feet Components: V, S, M (humanoid blood inside a ruby vial worth at least 600 gp) Duration: Concentration, up to 1 hour   You call forth a fiendish spirit. It manifests in an unoccupied space that you can see within range. This corporeal form uses the Fiendish Spirit stat block. When you cast the spell, choose Demon, Devil, or Yugoloth. The creature resembles a fiend of the chosen type, which determines certain traits in its stat block. The creature disappears when it drops to 0 hit points or when the spell ends.   The creature is an ally to you and your companions. In combat, the creature shares your initiative count, but it takes its turn immediately after yours. It obeys your verbal commands (no action required by you). If you don’t issue any, it takes the Dodge action and uses its move to avoid danger.  

Large fiend

Shape changer: The quasit can use its action to polymorph into a beast form that resembles a bat (speed 10 ft. fly 40 ft.), a centipede (40 ft., climb 40 ft.), or a toad (40 ft., swim 40 ft.), or back into its true form . Its statistics are the same in each form, except for the speed changes noted. Any equipment it is wearing or carrying isn't transformed. It reverts to its true form if it dies.