The caricature is most certainly racist. So you have two choices:
1- Acknowledge that the image is racist, explain the rationale for it and that you take responsibility for it. For example, in one of my webcomics some of the Romani characters describe themselves as "gypsies" (which is the equivalent to the N word.) Many non-Romani characters use this term as well in a derisive way since they are actually supposed to be bigots. Since word term is severely racist, but in context of the story is appropriate, especially since the comic is co-written by someone who is Romani, then I place a disclaimer explaining my rationale. Here's the example: http://barxotka.com/faq/#offended
2- Don't use that image if you aren't prepared to deal with the fallout it will inevitably bring on.
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