I don't know if there are any comic books created specifically for learners of German as a foreign language. But of course there are comic books (just as there are books and other media in general) that are created specifically for readers with a beginner level of the language: children. Media for children often have a more limited vocabulary and less complex grammar compared to media for (educated) adults.
So if you are open for or even interested in reading comics for kids, you will find some at each level of language skills. Just go to amazon.de, browse for comics or movies (pronunciation!) or whatever you want, and pick the adequate age group. Here's the direct link. (You don't have to limit yourself to original German works. Translations into German from other languages are usually as good as original works, linguistically. Also, I don't mean that you need to buy from Amazon, just that they list many comics and give you the best selection on the web including reviews. You should note though, that if you are truly interested in comics, a dedicated comic store has much that is not sold through Amazon, but I have yet to find a website that presents what Amazon does not have.)
On the other hand, I myself have learned English from reading Science Fiction in English since I was 14 years old. At first I needed a dictionary to get by, but after some time many of the words repeated themselves, because the themes and objects repeated themselves, so that I did not need the dictionary as much anymore. And many of the more common and non-science-fiction words I learned in the same way that children learn a language: by understanding them from their context.
So actually I believe that as soon as you had about two years of German at school (or the equivalent of two years with four hours or so per week), just grab any book you are interested in and work your way through it. Your interest will keep you reading and after a handful of books you will see how it gets easier very quickly. Movies are great, by the way, because with German subtitles and the ability to switch to English you have a full language course there.
In sum, I wouldn't recommend specific books (or comic books), but that you get books that you find interesting and actually want to read, because being interested will help you a lot with the frustration that you will definitely encounter.
If you specifically want to read comics by German authors, the most popular authors (among critic and readers alike) are:
- Ralf König
- Walter Moers
- Peter Puck
Good publishers are:
There are many more publishers, of course, but most publish both German and international authors and it will be difficult for you to discern who is who. A list of some publishers with some of their German authors is given on the website of the Goethe Institut.
If you like reading comics online, there is a comprehensive list of German language webcomics at Webcomic-Verzeichnis. The comics listed range from professional (by people who earn a living making comics like Flix) to amateur, with an equally wide range in quality, so you'll have to browse and see what you like. Don't give up too quickly, if the first few comics are not to your liking, there are true pearls there (and some dead links).
And beware! Not all German comics feature correct language! Sometimes their authors write slang intentionally, and sometimes they simply weren't good in school :-)