Morty: Why are you doing this?
Testicle Monster A: You think I wanna be an omniscient immortal being transcending time and space my whole life? I got ambitions man, bringin' you guys in is my ticket up.
Rick: What if I told you there's a huge ticket up right behind you?
Testicle Monster A: You really think I'm that stupid?
Rick: Alright, hear me out on this. You're immortal, right, which means your life is infinite. Well in that case there's 100% chance that you'll eventually do everything, including turning around to look behind you.
Testicle Monster A: I cannot argue that.
Rick: Ah, God, gross and weird!