My hero is a synthetic biologist of an ancient race that achieved spaceflight billions years ago. His bio ship could achieve high fraction of speed of light, and he could repair or modify his body or simply put it into hibernation so long travels doesn't worry him. For billions of years he wandered through the galaxy exploring, seeding, creating or modifying countless lifeforms on countless planets.
He visits a planet that he seeded long time ago, and finds that his creation evolved into intelligent beings that recently achieved spaceflight. Unfortunately their queen has a superiority complex and orders her minions to kill him.
How to gently teach her a lesson using biological or chemical means?
I want him to demonstrate that though they are many and he's alone numbers don't mean anything when he could easily beat them if he wants. I was thinking of using some kind of virus/bacteria, entomopathogenic fungi, airborne poison or maybe some irritant.
Creator doesn't have any interest of being worshipped by the created, nor any use for them or their resources. He was just interested to see how his work developed and get to know them. Soon he will be gone toward another planet that might be able to harbor life.