This Cat is currently not available in the English version of The Battle Cats.
KHM48 is an Uber Rare Cat created by a collaboration between mobile games Princess Punt and The Battle Cats. This character can be unlocked by playing the Rare Cat Capsule in The Battle Cats during said collab. This is one of the earliest Ubers in the game. Its true form was added in the 2017 collaboration event, which makes its status like a current Super Rare Cat.
Normal: Looks like a human girl/princess. Sits on a giant throne with flowers. Being carried by many normal Cats.
Evolved: Now has color. Sits on a different throne with spikes. Being carried by darker Cats with tentacles. Strongly resembles Dark Emperor Nyandam. Now with colors.
KHM48 is available in the English version but is obtainable only via hacks. The English name and description are abc03104 and "abc03105 abc03106 abc03107" respectively. The awkward entry seems to be a result of no actual English text.
The unit's appearance tends to mimic that of Dark Emperor Nyandam. They both sit on a throne and point with a finger. The cats that carry the throne resemble the evil spirits under Nyandam's throne.
KHM48's name could be a reference to Japanese musical/idol group AKB48.
When exchange for XP, KHM48 does not costs 1 million XP.