When you do, put a +1/+1 counter on each creature you control
Hangarback Walker Hangarback Walker is a great creature to invest out +1/+1 counters into
But we did get to see three cards
Archmage's Newt Bonny Pall, Clearcutter Breeches, the Blastmaker Canyon Crab Daring Thunder-Thief Deepmuck Desperado Djinn of Fool's Fall Doc Aurlock, Grizzled Genius Duelist of the Mind Eriette, the Beguiler Fblthp, Lost on the Range Geralf, the Fleshwright Geyser Drake Harrier Strix Jem Lightfoote, Sky Explorer Kellan, the Kid Kraum, Violent Cacophony Lazav, Familiar Stranger Lilah, Undefeated Slickshot Loan Shark Malcolm, the Eyes Marauding Sphinx Marchesa, Dealer of Death Nimble Brigand Obeka, Splitter of Seconds Outlaw Stitcher Peerless Ropemaster Razzle-Dazzler Riku of Many Paths Satoru, the Infiltrator Shackle Slinger Slickshot Lockpicker Slickshot Vault-Buster Spring Splasher Stoic Sphinx Visage Bandit Wrangler of the Damned