These are primarily obtained through the Cat Capsule (Gacha) . For the best results, save your Rare Tickets and Cat Food for "Uberfest" or "Epicfest" events, which double the Uber Rare drop rate from 5% to 10%.
These nine units are unlocked automatically as you progress through the early stages of Empire of Cats Chapter 1 . Battle Cats Unlocked All Cats
The rarest units in the game, these have a minuscule drop rate (typically 0.3%) and are never guaranteed, even during special 11-draw events. These are primarily obtained through the Cat Capsule (Gacha)