Pearl, Trusty Steed

Energetic - At the beginning of each opponent's upkeep:
if this creature is tapped, untap it and it gains indestructible until end of turn.
Hard to Keep Track of - Whenever Pearl attacks, if she
was saddled, exile her at the end of combat until your
next upkeep. Then return her to the battlefield and she
gains haste.
Saddle 3