>>16553168The fleshy part on top of their beak. It's sometimes sexually dimorphic, and males will often have brightly colored ceres compared to females who have dun ceres. Here's an example with budgies. The male is on the bottom and has a blue cere, while the female on the top has a plain cere. Male Floressums are supposed to have a green ceres while females have plain. I'll post the picture from Clash's dropbox showcasing this.