Zombies have a longer delay between attacks than antlions so if you can judge the delay between their attacks, you will be able to defeat zombies with less fear of being hit. And as you only start with 100 HP, and it's not easy to regain your life, your best bet would be to attack them with a weapon and kill them quickly, rather than take them on straight away. Though slow moving, they can deal 10 damage to you if you get too close. You'd be surprised how often people mistake this. All the other characters in the game are actual players.
Zombies, Fast Zombies and Antlions, straight out of the HL2 universe.
