Enemies

Bosses are on waves 9, 17, 25, 33, 41, 49, 57, 65, 73, 81, 89, 97, 105, and 121. A base needs to be strong to handle boss waves.

Zombies won't spawn at night until you place the gold stash. It goes on forever after tier 6 [orange zombies] at type 10, at wave 141.

Having more players in your party increases the number of towers and zombies.

Monsters

Monsters are zombies that are spawned around a ruby. They can also be known as Demons.

Normal monsters are not hostile to the player unless they attack first, and will ignore you if you run away. They are a hassle to deal with and do not provide a reward when they are killed, so you should obviously ignore them.

Every 8 waves, an extremely large, powerful Monster will appear as a boss. Even if you are well-prepared, it can and will destroy almost anything in its way of the Stash in just a few hits, and takes quite a lot of hit before it goes down!

Unlike the type of monsters that live around those red rocks called camps, No Mercy is an actual monster. Kill him to upgrade your pets!

Players

Other players in your server might cause significant annoyances and they are the only PvP action you'll ever get in this game.

They might attack your base, spam your chat and kill you. While that might be symptoms of No LIfe Disease, players are easy to counter.

Symptoms of No Life Disease