Tally Counter

The Tally Counter is an equipable accessory that displays how many monsters one has killed. It is one of the three parts necessary to make the R.E.K. 3000, with the others being the Lifeform Analyzer, and the Radar. When equipped or left in one's inventory, the Tally Counter will first display that no kill data is available. After an enemy has been attacked, the text will display how many times the character has killed that enemy throughout the character's entire life time. The text will display that kill count until different enemy has been attacked.

It has a small chance of being dropped from enemies in the Dungeon, however it only appears to drop pre-hardmode.

Trivia

 * A character's kill count is kept track of even before a Tally Counter is acquired.
 * Enemies without a respective banner do not have a kill count, and the Tally Counter will instead display that no kill count is available.