Tiddlet
Tiddlets are small, furry creatures introduced in The trouble with Tiddlets contract in which the Tiddlet Breeder asks the player to deliver a small group to the end of the sector. A Shady Buyer contacts the player and offers to pay extra for the Tiddlets for mysterious purposes.
Tiddlets breed telepathically and multiply during every FTL Jump the player takes. They can quickly overrun a ship, leading to offloading times that can sometimes result in ships running out of resources.