YouTube/The Seattle Times
Froemke, a former bodybuilder, has his body painted like The Incredible Hulk for every home game and is a regular fixture in the front row. According to The Seattle Times, Froemke's body paint is part-superstitious, having first transformed into Seahulk for the Seahawks win in the 2005 NFC Championship game win.
Since then, Seahulk's paint job has evolved from something fairly simple, to something that takes three hours to complete before every game by a professional body painter. Here is a comparison of Seahulk from a game earlier this season (via Twitter/CJZERO) and from the 2005 NFC Title game (inset, via AP). A time-lapse video can be seen below (via Seattle Times).
Here is a time-lapse video showing the 3-hour transformation.