The Blue I is the rarest Mob in the game. It will steal items from your inventory.
This is the rarest of the Mobs by far; it is bright blue in color and about 3 times the height of a block. In the TODO file containing programmer's notes, it is called the "Monkey".
The Blue I is passive until shot or until approached closely. It is 3 blocks tall, about 1 block wide and half a block thick. It has 2 short legs that can only be seen while it is walking.
In creative mode, shooting it will turn it 'hostile'. It is already hostile in explore/survival mode, but cannot harm you. When they turn hostile, it will then run after the player, touch them and then steal an item from their inventory. A message then appears saying An item has been stolen!. It then seems to teleport away from the player, found afterwards with your item. To retrieve the item, you must kill the Blue I.
When a Blue I teleports, it has been observed falling out of the sky a short distance away onto a patch of ground. It is theorized that it falls all the way from the top of the sky.
Killing the Blue I before it steals everything will cause it to drop a random object. With Slug Pistol V1, it takes 1-2 shots to kill one.
Blue I's commonly move slowly, but if one is chasing you, they can be quite fast. They can jump about 6 blocks high to reach the player or to get out of a pit, yet when they are neutral towards the player they will only jump one block high.
When the Blue I "walks", its 2 stubby legs make short quick strides. Aside from Space Giraffe, other mobs in Lunacraft appear to hover above or slide along the surface.