Looker was introduced in Pokemon Platinum and has made many appearances in the games and anime since then. So naturally he’d be included in SM5 since the set is all about Sinnoh!
Draw 3 cards from the bottom of your deck.
You may play only 1 Supporter card during your turn (before your attack).
Basically, Looker is another Hau type card, but from the bottom of the deck. Interesting. It’s a slightly different reprint of Underground expedition from Expedition. (Below). I believe this card got a re-print in one of the diamond and pearl sets, but looker gets you 3 cards instead of choosing 2 cards from 4.