The 杀怪计数器 is an 信息 配饰 that displays how many monsters have been killed. It is one of the three parts necessary to make the R.E.K.3000, with the others being the 生命体分析机, and the 雷达, and as such is a required ingredient in making the 手机. When equipped or left in one's 物品栏, the Tally Counter will first display "Kill count unavailable" underneath the map/health area. After an enemy has been attacked, the text will display how many times that enemy has ever been killed by players in that world. The kill count will only display the last enemy struck by you or your minions. It will count deaths from world creation rather than from when it was equipped. It can be very useful when trying to acquire a specific monster banner, which drop in increments of 50.
- This device works based on the world's kill count of each enemy, not the individual character's. This can be observed when travelling to a different world, as well as during multiplayer, each kill counts towards the total.
- Enemies without a respective 旗帜, such as Bosses, do not have a kill count, and the Tally Counter will instead display that no kill count is available.
- Certain 困难模式 versions of pre-Hardmode enemies do not have a kill count, and will instead share the kill count and banner of their pre-Hardmode counterpart.