Aeromunculus Basking Broodscale Benthic Biomancer Cursed Wombat Dreamdrinker Vampire Emperor of Bones Etherium Pteramander Evolution Witness Expanding Ooze Fetid Gargantua Growth-Chamber Guardian Hydra Trainer Incubation Druid Jetfire, Air Guardian Knighted Myr Pteramander Sauroform Hybrid Scuttlegator Sharktocrab Skatewing Spy Skitter Eel Temperamental Oozewagg Trollbred Guardian Unruly Krasis Zegana, Utopian Speaker
Graveyard hate (its activated ability can target any graveyard), card selection, recursion, life loss The Scarab God has it all
For Ghost-type fans Gengar & Mimikyu GX
It may be somewhat overcosted at 6G, but in a deck focusing on green mana, this Sorcery can utterly flood the board with Wolves that will overrun your opponents with ease
But often it is for mutual benefit or the benefit of a single player, not a big deal on its own, except when two friends use Trade Secrets to draw their whole decks and go into a war to combo off while the rest of the table is blown away