The Lieu Monster, nicknamed Lieu by Oguma, is the Final Boss of Metal Slug 3D after Lugus
This monster is out from another Lugus body just like on the cutscene, It traps you and The SV-001 inside it, you have to Shoot his eye when his eye is open.
He's shoots laser with many eyes (Not the main Eye) It punches you with his arm and when he finishes punching it will kick you with his Leg that falls from roof. When his eyes open he attacks with falling heads, if you cannot clear the two arms in the beginning, the Lieu Head will eat you and his eyes will close again.
When he's dead, he will start screaming and heads fall down. He is eventually destroyed by Oguma's forces with the help of a light-reflecting disc as the Regular Army flees.