Silithus 

One of the biggest time sinks in the MMORPG called World of Warcraft. People used to spend months getting reputation with the collected people, or Faction, of Silithus. May be used as a description of a time sink or something that takes way too long to finish (if ever finished).
If looking for annoyances that are synonymous, might I suggest looking up Barrens Chat?

Person 1: I swear, I was mowing lawns for my neighbors this last weekend, and this one lawn was a total Silithus.
Person 2: You poor, poor soul.

Silithus by Hondow November 30, 2010

silithisis 

A psychotic snake that ravages the homeless people on the streets of New York. He is rumoned to be over 28 feet long, and can travel at speeds of up to 161 feet per second. A "silithisis" feeds mainly on black people that are homeless, but if tempted, he will eat the Irish.

As Jerome was selling his 99 cent watches, a silithisis engulfed him in a swift bite.

silithisis by Chodehead May 13, 2005