Rukarumel, Biologist

As Rukarumel, Biologist enters the battlefield, choose a creature type.
Slivers you control and nontoken creatures you control are the chosen type in addition to their
other creature types. The same is true for creature spells you control and creature cards
you own that aren't on the battlefield.
{3},{t}: Create a 1/1 colorless Sliver creature token.
"On to the next place to do some research."
—Jiraiya