Intentionalmisspelling of "huge" for comic effect and emphasis. It means the same thing as huge, but can have additional connotations to it; see example.
The pronunciation of HUEG is unclear. Four possible pronunciations are <hyooj>, <hyoog>, <hoog> and <hwayg>.
1.
Person A. D00d, I has a HUEG paper 2 rite 4 english clas T_T T_T T_T
Person B. You're gonna fail.
2.
C. I thought all the HUEG guys could crash through walls in this game.