Crystal Crabal
From IdleOn MMO Wiki
The Crystal Crabal is a rare mini-boss that has a 1 in ???? chance to spawn whenever you kill an enemy in the second world. His stats change depending on what area you are in. You can increase the chances of it spawning using the Crystals 4 dayys special talent, with the Crystallin Stamp or the third bonus of the Non Predatory Loot Box in the Post Office.
Crystal Crabal has ?? hp, ?? exp, ?? defence (which directly affects accuracy needed to hit) and ?? more damage than the enemies in the area it spawns in.