Previous Versions can be found here.

The Janitor was added in Beta 5.8 with the ability to give +1 ATK to monsters on its right and +1 HP to those on its left, loosely based off how the Janitor makes a mess of the left and right continuously because of his dripping slime.

This makes it a strategic but useful card, especially in the early to mid game of a match because of its decently low cost. It may be particularly useful in decks that are reliant on buffs such as Bravery.