Although it costs three mana to cast, which is a bit high for a mana rock , its effect is more than worth the cost, especially in a deck that cares about drawing cards
Elesh Norn, Mother of Machines This five-drop 4/7 legendary dork has vigilance, which is better in multiplayer since you can swing at the open player without opening yourself up to multiple counter attacks from everyone
Many dragons like Chiss-Goria, Forge Tyrant and Blast-Furnace Hellkite have an artifact tie-in
Each player who didn't choose the lowest number discards their hand, then draws seven cards.
One last note, going forward I will be referring to all of these partner-like mechanics as partner
if the target dies or gets sacrificed in response, you dont get to proliferate