The Bacterial Bloon is a black bloon with a biohazard symbol on it. When it touches any bloon that's in the affectable list, that bloon will also become a Bacterial Bloon, but once a Bacterial Bloon is popped it can't become a Bacterial Bloon again even when "infected". When a Bacterial Bloon is popped, it'll spawn one of each of the affectable bloons.

Affectable bloons: Red, Blue, Green, Yellow, Pink, Purple, Black, White.