Max Ooze inflicts damage and then raises the user's and its ally's Special Attack by one stage. Its power and whether it is a special or physical move depends on the move it is based on. Compared to the other Max Moves, it usually has less power.
Gigantamax Gengar releases a wave of purple sludge from its body at the opponent. It can also manipulate the sludge, sending streams of purple poison to attack the opponent.
This article is part of Project Moves and Abilities, a Bulbapedia project that aims to write comprehensive articles on two related aspects of the Pokémon games.