Subscribe to download
Zombie++

This is a very simple addon, that makes zombies and headcrabs more powerful, by making headcrabs, able to really crab on npcs' head (and even players') and by making zombies spread the "virus". It is working with all the zombie types, and with barnicles too. Also, the transforming is instant.
List of working npcs:
mossman
monk
metropolice
kleiner
gman
alyx
eli
combine
citizen (a lot other addons use citizens to make npcs, so most of the addons will work wiht Zombie++)
breen
barney
VJ's scientists
Combine assasin

If you want a new npc to be added, suggest it in the comments.

We have convars too! YAAAY!
zpp_player: Can players can be zombies too?
zpp_barnicle: Can barnicles create zombies?
zpp_headcrab: Can headcrabs create zombies?
zpp_heal: If a zombie kills an NPC, should the zombie heal?
zpp_head: Spawn headcrab zombies with a headcrab
zpp_forcehead: Spawn any type of zombie with a headcrab
zpp_chance: The chance of becoming a Zombie on a 0-100 scale.

GitHub[github.com]
Do you have an issue? Tell it! [github.com]

Have FUN!