After calling out Buc-ee's for suing smaller companies over animal mascots, British comedian and host of HBO's "Last Week Tonight," John Oliver launched a parody shop benefiting Hunger Free America. The campaign has brought in nearly $500,000 while drawing fresh attention to the expense and pressure those trademark fights can place on local companies. Here's what to know As Good Good Good reported, Oliver followed his July 27 segment on Buc-ee's…