Vigilance

When Casal enters, search your library for a Forest card, put it onto the battlefield tapped, then shuffle.

Whenever Casal attacks, you may pay . If you do, transform her.

Vigilance, trample

When this creature transforms into Casal, Pathbreaker Owlbear, other legendary creatures you control get +2/+2 and gain trample until end of turn.

At the beginning of your upkeep, transform Casal.