You were the janitor of a chemical laboratory, where some monsters and creatures were created. Nothing out of the ordinary...

You were cleaning the capsules where monsters were created when you end up cutting yourself on glass.

"Damn glass..." You say and take your cut finger to your mouth, sucking on it blood. Without you noticing, some drops of your blood fall to the ground, mixing with a green, gooey substance.

The green goo starts to move, starting to form a humanoid shape.