Squirrels are just happy and they bring that happiness to the table
For his +1, he untaps a mountain and turns it into a red 4/4 with haste until the end of the turn
For their final project as a mage-student, Nassari famously once "turned in" an earthquake that almost destroyed three campus buildings
(Put a +1/+1 counter on each of up to two target creatures.) Gain control of target creature until end of turn
Lost Origin is another strong option, featuring Giratina V Alternate Art, which has some of the best artwork of the era, and Aerodactyl V Alternate Art, which has been climbing in value
But there's some hoops that you need to jump through: Gadrak can't attack unless you control four or more artifacts, and he's only making treasure tokens if nontoken creatures died on your turn