Heck, Crypt is played less than Hedron Archive
It lasts until Gigantoplasm leaves the battlefield or another effect overwrites it (for example, if you activate the ability again once you have more mana available)
A sign at the bottom of a card or next to its name means it is rare
Blackcleave Goblin Blight Mamba Blighted Agent Blightsteel Colossus Blightwidow Burn the Impure Carrion Call Chained Throatseeker Contagious Nim Core Prowler Corpse Cur Corrupted Conscience Cystbearer Fallen Ferromancer Flensermite Flesh-Eater Imp Glistener Elf Glistening Oil Grafted Exoskeleton Hand of the Praetors Happy Dead Squirrel Ichor Rats Ichorclaw Myr Inkmoth Nexus Lost Leonin Melira, Sylvok Outcast Mindcrank Necropede Ogre Menial Pestilent Souleater Phyresis Phyrexian Crusader Phyrexian Digester Phyrexian Hydra Phyrexian Juggernaut Phyrexian Swarmlord Phyrexian Unlife Phyrexian Vatmother Plague Myr Plague Stinger Priests of Norn Putrefax Razor Swine Reaper of Sheoldred Rot Wolf Scourge Servant Septic Rats Shriek Raptor Skithiryx, the Blight Dragon Skithiryx, the Blight Dragon Spinebiter Tainted Strike Tangle Angler Tel-Jilad Fallen Tine Shrike Toxic Nim Trigon of Infestation Triumph of the Hordes Vector Asp Viral Drake Viridian Betrayers Viridian Corrupter Whispering Specter
Let the folks play with their creepy toy
Weaker typal themes, like Cats and Dogs, for example, are perfect
