Hey Sanne, welcome to Proko! The master of (teaching) animal art, hands-down, is Aaron Blaise. He has a masterclass for sale here on Proko of drawing a lion in charcoal, but you should also check out his website, too, if you're not familiar, as well as his YouTube (which is more animation focused, but still). Not to direct you away from this website, Proko is great for learning to draw any kind of realism, but there aren't many animal centered courses here. Aaron has so many awesome courses for sale on his site, and almost all of them have something to do with animals. And he is an incredible teacher. You won't be disappointed. CreatureArtTeacher.com (Hope the mods don't mind me linking Aaron's site.) If you want to try out some creature design courses, there's a few of those, but those aren't necessarily real-life animals but mythical/monster type things. But they will get you into creating "animals" from imagination, which it sounds like is something you're interested in? Check out Scott Flanders and David Colman. Their courses always get high marks. Good luck! Don't be afraid to reach out with questions.