Mamba is partially in reference to a snake being phallic (because for the life of me I can't think of anything else inappropriate one could derive from it), it's news to me that anybody makes that connection instead of the fact that it is fast, venomous and feared.

So if it's not that, then you must be considering the ginger part of the name inappropriate, which, is also silly, since the word has become very mainstream, and even red-heads generally own it.

Color me confused, I guess. I think the name is hilarious.