The word BakeNezumi Is presented without Kanji, but obviously derived from real Japanese words. It could possibly be translated as Monster/Mutant Rats, but neither of these really does it justice. Some translators of the Anime have translated it as ‘Queerats’ using the definition of queer as something unusual in a strange and/or unsettling way, but this doesn’t really feel right to me either, so I left the word as is.