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 1 February 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 1 February 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.