Twinkie is a term used in
gaming circles to refer to someone who
tweaks their
character to the max using stupid exploits of the rules.
"Oh look! Thanks to alternate character generation method #89, I have an Intelligence of 30, making me invulnerable to all spells except those cast by Deities or Gary Gygax!"
The tendency to "twink" their characters to the outrageous is what earns them the derogatory nickname of Twinkie.