Shocker zombie/doc
Every 25 turns, a shocker zombie can shoot a stream of electricity at the player; it can paralyze you for a few turns, so be careful around groups. It's fast at 105 speed so if trying to avoid you'll likely have trouble simply running. Try to break its line of sight and find cover in close and rugged terrain, preferably a forest or a building with lots of furnishings.
Attacking a shocker in melee with any weapon will electrify you. As of 0.E (Ellison), you cannot hit a shocker with any melee weapon, wooden or not, without being shocked, so the only way to deal with these creatures without being shocked are with firearms, throwing weapons or explosives, if you don't have any ranged weapons, avoid these monsters and run if they see you.
Shockers produce a tiny amount of light and so are visible even in total darkness.