Let's use Tuinvale Treefolk as the creature for this example as it has no abilities on its creature side.
This is relevant for Ruxa, Patient Professor and Muraganda Petroglyphs.
Does the answer change when the creature is in the graveyard? (this is relevant for Ruxa's first ability)
What about in the hand, in case a card existed that let you put a creature with no abilities into the batlefield?