For those just tuning in, the enemies in Sunset Overdrive are mutants, transformed by a toxic energy drink called Overcharge. The most basic of these is referred to as an "OD," since they've overdosed on the drink. These zombie-like minions gather in hordes to swarm the player with melee strikes. Meanwhile, "Blowers" can launch Overcharge at range and "Herkers" charge forward like the walking tanks they are.
Not everyone has turned into a monstrous shadow of their former selves, however; some people are just jerks. Non-mutated humans, called "Scabs," will also show up to fire assault rifle rounds at your decidedly non-bullet-friendly body. The Scabs will target mutants as well, leading to cross-faction warfare.
Insomniac promises that players will encounter even more enemy types throughout the game, leading to all kinds of crazy encounters. We'll find out when the game hits shelves on October 28.