You are free to copy, share, sell, remix, modify, fold, bend, staple, and mutilate Mimi & Eunice but you may not prohibit others from doing the same with any resulting copies or “derivative works“. You may include Mimi & Eunice in larger, copy-restricted works (like textbooks, magazines, movies, TV shows, etc.) but the Mimi & Eunice parts must remain under the Share Alike license (aka Copyleft). This is easily achieved by marking the Mimi & Eunice parts “CC-BY-SA Nina Paley” or “copyleft Nina Paley,” even while the rest of your work is under copyright or whatever godawful restrictive license you use.
Please do not imply you, or anyone other than me (Nina Paley), created existing Mimi & Eunice cartoons. The CC-BY-SA license prohibits fraud and plagiarism, but I really think you know better than to do those things even without the threat of legal force, if for no other reason than self-preservation and not wanting to ruin your credibility and become a laughingstock and pariah.