Siphon

Whenever this Pokémon uses a move that drains HP from the opponent or passively regenerates HP (Absorb, Mega Drain, Giga Drain, Leech Seed, Leech Life, Dream Eater, Drain Punch, Horn Leech, Draining Kiss, Parabolic Charge, Oblivion Wing, Drain Life, Vampire Fang, Ingrain and Aqua Ring), the HP restored is increased by 1.3×. Siphon does not increase the damage inflicted by the move itself.

This effect stacks with Big Root, such that HP-draining/regenerating moves will instead increase the HP restored by 1.69× while holding one.

If the target has Liquid Ooze, the HP lost is also increased by 1.3× (1.69× while holding Big Root).