It puts your opponents in a lose-lose situation: Either they leave your Dragons alone and get crushed, or they try to remove them and bleed out from repeated burn triggers
Rishkar, Peema Renegade : Legendary Creature (Elf Druid), casting cost of two generic and one green mana, 2/2
For new Magic: The Gathering players, the Arena code cards are especially useful
Ooze is once such type, slowly seeping its way into contention through a series of surprisingly good legendary options
Take as two good examples Derevi, Empyrial Tactician, who has an alternate play cost, and Oloro, Ageless Ascetic that always nets you life even when it's in your Command Zone