Rare Kittens have identifiers beginning with 0x01. There is a 5% chance a kitten is born Rare, this attribute has a powerful hidden Luck amplifier that can sometimes turn outcomes in your favour.
Mutant Kittens are born with mutated identifiers, which isn't necessarily a bad thing! They are likely to behave erratically which can sometimes be a good thing as you'll find out soon.
Hover over a Kitten to view its Attributes. These traits and modifiers affect how your Kitten will perform when used in the companion application