If used by a transformed Pokémon, it will display a shorter animation with the transformed Pokémon stuck in a default pose. However, it cannot be copied by Copycat.
Behemoth Blade and Behemoth Bash are not present in the mobile version of Pokémon HOME's move Pokédex. This is because they would be impossible to register, since the forms of Zacian and Zamazenta that they are the signature moves of can only appear in battles and therefore cannot be deposited into Pokémon HOME. They share this distinction with Glacial Lance and Astral Barrage, which are also the signature moves of forms that cannot be deposited into Pokémon HOME. Notably, Ice Burn and Freeze Shock are present in the move Pokédex (despite also being the signature moves of Pokémon that cannot be deposited) due to the fact that Smeargle can learn them with Sketch.