Final answer:
The metaphor describes someone as isolated and engrossed in escapist hobbies, with a sense of self-deprecation and detachment from active societal engagement.
Step-by-step explanation:
The metaphor "I'm just this critter hiding out in the basement, drooling in my comic books or whatever" describes a person who sees themselves as insignificant, isolated, and perhaps engrossed in escapist hobbies like reading comic books, away from the demands and judgements of the outside world.
This imagery conjures up feelings of self-imposed solitude and a possibly unfavorable self-perception. The mention of 'critter' and 'drooling' also suggests a sense of self-deprecation and a picture of someone not actively engaged in the vibrant part of life but rather in the shadows, detached from society's mainstream activities.