"As you see, these flowers . . . can have either restorative or poisonous . . . what is that?"

Herbology Instructor

When Herbology Instructor enters the battlefield, you gain 3 life.
{6}{B/P}: Transform Herbology Instructor. Activate only as a sorcery. ({B/P} can be paid with either {B} or 2 life.)

"How dare you leave before my lesson is done!"

Malady Invoker

When this creature transforms into Malady Invoker, target creature an opponent controls gets -0/-X until end of turn, where X is Malady Invoker's power.

Herbology Instructor // Malady Invoker

When Herbology Instructor enters the battlefield, you gain 3 life.
{6}{B/P}: Transform Herbology Instructor. Activate only as a sorcery. ({B/P} can be paid with either {B} or 2 life.) 

 When this creature transforms into Malady Invoker, target creature an opponent controls gets -0/-X until end of turn, where X is Malady Invoker's power.

Herbology Instructor // Malady Invoker

Creature — Treefolk Druid // Creature — Phyrexian Treefolk