Gensokyo/Kappa Adventurer

The Kappa Adventurer is a Hardmode enemy which may spawn in any body of water within the Hallow biome (including the Underground Hallow). She will approach the player while periodically firing a mortar shell into the air using her Crystal Shard Mortar. The shell will split up into multiple smaller projectiles while falling down.

Kappa Adventurers drop between three and six Point Items, a small amount of Hydro Charge ammunition, and may also drop Broken Kappa Technology, a material used to craft Kappa weapons and the Experimental Transmitter, which is used to summon Nitori Kawashiro.

The Kappa Adventurer counts as a Kappa enemy, thus, killing enough of them (30) will summon Nitori Kawashiro.