M

8 cards have the "M" tag (25 including reprints, mirrors and so on): 8 Pokémon and 0 Trainer cards.

Breakdown

All 8 matching cards are shown. "Source" shows which part of the card the tag comes from, and "Effect" shows that text.

Card name	ID	Source	Effect
Meltan	A1_181	Attack	Take a Metal Energy from your Energy Zone and attach it to this Pokémon.
Dialga ex	A2_119	Attack	Take 2 Metal Energy from your Energy Zone and attach it to 1 of your Benched Pokémon.
Gholdengo	A2b_057	Attack	Flip a coin for each Metal Energy attached to this Pokémon. This attack does 50 damage for each heads.
Probopass	B1a_053	Attack	Take 2 Metal Energy from your Energy Zone and attach it to 1 of your Benched Pokémon.
Genesect	B1a_054	Attack	This attack does 20 more damage for each Metal Energy attached to this Pokémon.
Orthworm	B2a_077	Attack	Take a Metal Energy from your Energy Zone and attach it to 1 of your Benched Pokémon.
Gholdengo ex	B2a_078	Attack	1 of your opponent's Pokémon is chosen at random for each Metal Energy attached to this Pokémon. For each time a Pokémon was chosen, do 40 damage to it.
Mega Metagross ex	B4_109	Attack	This attack does 10 more damage for each Metal Energy attached to this Pokémon.