You can use each effect among the (1) and (2) effects with this card’s name only once per turn.
(1) You can target 1 monster you control with 0 ATK and 1 DARK Reptile monster in your GY; destroy that first monster on the field, and if you do, Special Summon that second monster in your GY.
(2) If your opponent activates a monster effect: You can target 1 face-up monster they control with 0 ATK; take control of that monster, then Special Summon 1 “Reptilianne Token” (Reptile/EARTH/Level 1/ATK 0/DEF 0) to your opponent’s field.