The pig rabbit one is Changbin's mascot lol. It's because Changbin once drew a rabbit and the members mistook it as a pig, so he's like "it's pig rabbit!!", and later it became his mascot in skzoos.
I learn things from stray kids and gain their habits...i had a banana at school and i had just thought, hmmm what would stray kids do? because i think of them 24/7, so i took a bite the same way Felix did and when I tell you my friends looked so weirded out and disgusted it was so funny. they proceeded to ask me why, my only answer was "I saw Felix do it once".