Sludge

Sludge is a boss in Golden Sun: Dark Dawn. It is a lizard-like monster that haunts the Phantasmal Bog and, by extension, Kolima Village. It has a resistance to Mercury attacks and a weakness to Jupiter. It is accompanied by a Shield Skull and a Haunt Skull.

Some of its known techniques include:
 * Crush (target: single character)
 * Tail Slap (target: 3 characters)
 * Call Skull (summons a member of the Skull monster line)
 * Healing (heals up to 300 HP)

Defeating it will reward players with varying amounts of experience points and coins, dependant on how many Skulls were defeated. Also, Matthew can acquire the Crush Tusk after returning to Kolima.