Transform Rule 701.27 Glossary

To turn a double-faced card so its other face is up. See rule 701.27, “Transform.”
Vigilance Rule 702.20 Glossary

A keyword ability that lets a creature attack without tapping. See rule 702.20, “Vigilance.”

Rulings (4)

January 22, 2011 Wizards of the Coast
If you gain control of a Loyal Cathar owned by another player and it dies, it will be put into to its owner's graveyard and then return to the battlefield under your control.
January 22, 2011 Wizards of the Coast
Another double-faced card that becomes a copy of Loyal Cathar and then dies will return to the battlefield with its back face up.
January 22, 2011 Wizards of the Coast
When Loyal Cathar dies, it will return to the battlefield with its back face (Unhallowed Cathar) up. It doesn't return to the battlefield and then transform.
April 8, 2016 Wizards of the Coast
If a card that isn't a double-faced card becomes a copy of Loyal Cathar (due to Cytoshape, for example) and then dies, that card won't return to the battlefield. It will remain in its owner's graveyard.