Historical Rules · 7 June 2024
Rule 702.71a
Official source text from the 7 June 2024 Rules release
Transfigure is an activated ability. “Transfigure [cost]” means “[Cost], Sacrifice this permanent: Search your library for a creature card with the same mana value as this permanent and put it onto the battlefield. Then shuffle your library. Activate only as a sorcery.”