Now, for my Challenger. This is one I may have brought up before, but lord knows it's worth a chuckle.
This was a character designed for what we decided was going to be a serious, long campaign. It was made and designed by a person who says he had played D&D for 10+ years, ever since he was in middle school. It is a character he had been thinking about for years, and later revealed that he had even written stories about him.
To begin with, it's almost entirely custom. Custom class, custom race, custom abilities, custom items. The majority of the rest of the character, such as the variety of poisons he carried, comes from Nonwizards published books, such as the Assassin's Handbook. If any of you have seen that thing, stifle your laughter for now.
The race is a Lolth-touched drow. It's essentially a drow with pure red eyes, small horns, four spider legs on his back (which could make claw attacks), the ability to levitate a foot off the ground at will, damage reduction, energy resistance, bonuses to dex and cha, spell resistance, the traditional 120ft drow darkvision, drow weapon proficiencies, and the ability to produce webbing that was both stronger than steel and lighter than silk, which he could use to make armor and weapons, as well as stick to ceilings and support his weight. The silk could be produced at will.
The class is a custom necromancer. A sorcerer, that in exchange for a few spell slots (1 per spell level), gained the ability to know extra necromantic spells as well as animate dead as a spell like ability. He also had a familiar, a winged snake that could create a fear effect at will.