Card text
Choose a Basic Darkness Pokémon in your discard pile. Switch it with 1 of your Pokémon in play. Any attached cards, damage counters, Special Conditions, turns in play, and any other effects remain on the new Pokémon.

Nanu is a Trainer card. The listed subtypes are Supporter.
Nanu sits at 179/181 in Team Up, position 181 of 198. Before it is 178 Morgan, and after it is 180 Nita. The set belongs to the Sun & Moon series. It was released on February 1, 2019. The printed size is 181. This checklist is longer, at 198 cards. The listed rarity is Rare Ultra.
The card text says: Choose a Basic Darkness Pokémon in your discard pile. Switch it with 1 of your Pokémon in play. Any attached cards, damage counters, Special Conditions, turns in play, and any other effects remain on the new Pokémon. The card text says: You may play only 1 Supporter card during your turn (before your attack).
The illustrator line reads Hitoshi Ariga. I count 155 other cards in the catalog with that illustrator.
Team Up set binder is where a full Team Up set goes. This card fills one slot there. I still need this card.
Choose a Basic Darkness Pokémon in your discard pile. Switch it with 1 of your Pokémon in play. Any attached cards, damage counters, Special Conditions, turns in play, and any other effects remain on the new Pokémon.
You may play only 1 Supporter card during your turn (before your attack).
Team Up, in the Sun & Moon series. It was released on February 1, 2019. The printed size is 181.
179/181. It is entry 181 of 198 in this checklist.
Hitoshi Ariga. The catalog lists 155 other cards with that illustrator.
Rare Ultra.