Adventurers plops, ripe for the grabbing

You are a retrovirus and you have learned to control the thoughts of your host, a 47-year-old alcoholic recluse estranged from family and friends.

As a retrovirus, you have the capability to change your host's DNA, amounting to actual physiological changes, so as to accommodate your parasitic, reproductive ass. After reaching the brain, you've learned that you can't replicate in just this one host forever.