Paleozoic Hallucigenia

Target 1 face-up monster on the field; its ATK and DEF become half its current ATK and DEF until the end of this turn. Once per Chain, when a Trap Card is activated while this card is in your Graveyard: Special Summon this card as a Normal Monster (Aqua/WATER/Level 2/ATK 1200/DEF 0). (This card is NOT treated as a Trap Card.) If Summoned this way, this card is unaffected by monster effects, also banish it when it leaves the field.