From Michael Quinion’s World Wide Words #674 (1/27/10):
AVATARD A chorus of disagreement came from readers over this. All were sure it’s from “Avatar” + “retard”, as are “celebutard” and a few other slang terms, using “retard” in its current abusive sense of a mentally retarded person. Another term of similar origin, I am told, is “freetard”, which was supplied by several correspondents. Jeremy Ardley described it thus: “it’s an epithet used by those who pay for their software for those who choose to use free open-source software. The implication is that if you get it for free it ain’t worth diddly-squat and you’re mentally challenged if you choose to use it.” Others mentioned politically motivated insults of similar formation, such as “conservatard” (by coincidence, my newspaper last Sunday included the related term “Libtard”, though the initial
capital letter showed that it referred specifically to the British
Liberal Democrat party).
And then:
AFFIXES Various comments on word endings last week and this have persuaded me to add three entries to my site about the building blocks of English: the three are “-tard“, “-flation” and “-naut“.
Ah, here’s a topic that combines three of my interests: playful word formation, portmanteau words, and the “liberation” of parts of words (like the three Quinion just listed), to yield word-forming elements that are semantically like the elements of compounds but are affix-like in that they are typically bound.