add new NPC : Mortar Bug

fix eggs BUG

You can now burn the parasite eggs at any time and it will spawn a burning parasite


fix Harvester spawn BUG
now Harvester will spawn the parasite（exp）when it close to the player

Fix the parasite to kill the enemy's infection probability
Now, the parasite will infected enemy If it killed the enemy

You can stop the infection if you can get rid of the parasite or kill the infected object of the parasite