Jazz

Few crossover events manage to unite two of pop culture's most beloved universes, but Jazz arrived in exactly that collision point — Marvel's 2007 limited series New Avengers / Transformers, brought to life by Stuart Moore and Tyler Kirkham. This Modern Age character shares the page with heavy hitters on both sides of the aisle, from Optimus Prime and Bumblebee to none other than Captain America himself, making for one seriously star-studded roster. With only four catalog appearances, Jazz is a rare find tied to a genuinely unique moment when Earth's Mightiest Heroes and the Robots in Disguise occupied the same story — a collector's curiosity that captures the fun, anything-goes spirit of crossover comics at their most ambitious.