One who posts confusing, nonsensical, nearly indecipherable posts on a web forum.
The descriptive was coined after McDoom, a poster on several internet toy discussion forums, managed to accumulate an almost unfathomable amount of disturbingly incoherent posts, each one funnier than the one before, in the span of a few months.
The only remaining fragment of McDoom's rantings is an oft-quoted segment of a lenghty, sequentially numbered tirade against Toy Biz (currently Marvel Toys) over one of the mid-range Marvel Legends lines:
"3. I AM HAVE BIRD"
One who does this now is said to be "McDooming" as the members of the aforementioned forums never truly believed the poster to be real, but merely an identity constructed in order to conduct an experiment in creative writing.
1. Descriptive - "What McDoom here is ranting about has nothing to do with the subject at hand."
2. Verb - "McDooming my thread with off-topic replies doesn't change the fact that you're wrong."