Dallas and Muddy Grimes

Dallas and Muddy Grimes are a couple of arms dealers, old foes of Agent Flemming and the ATF, that appeared in Beavis and Butt-head Do America.

They stole the X-5 bioweapon with intent to sell it, but had a violent falling out - Muddy went to Highland to hire a hitman to "do" his wife, what he got was Beavis and Butt-head misunderstanding the order, and Dallas would manipulate the boys to transport the weapon across state lines. In the end, both were captured but Dallas was able to turn states evidence.

Daria Morgendorffer was at school when all this happened, only knowing the ATF raided it and cavity-search Mr. Van Driessen while looking for Beavis and Butt-head. Despite that, fanfics have been making use of the Grimes for years!