I have Heavy Weapons Guy with a loadout of Minigun-Shotgun-Fists of Running Urgently, Rainbow Dash, and the Hero of Time as an adult.
Heavy would be able to slaughter zombies by truckloads, provided he had someone to keep them off his back. However, he'd run out of ammo quickly, and the Fists would make him more susceptible to damage to make up for their speed boost.
RD would have a great chance of surviving, unless there are flying zombies

. She could also work as an assassin, taking out any above-average zombies with a dive-bomb.
Link has Fire Arrows and Din's Fire, which would be awesome for purging the undead in flame until his magic runs out. Sun's Song and the Longshot would likely stun zombies in a nearby radius, so he could use the Master Sword to finish them off. Bombs could be used to create makeshift bridges and shelter. All-in-all, a quite versatile ally.
edited 22nd Aug '12 11:57:19 AM by SuperGex
Back in Black, and by black I mean BLU.