Opabinia the Five Eyed

Trample, Vigilance
If the Era is Cambrian, Opabinia gains Lifelink and Islandwalk
If the Era is not Cambrian, Opabinia loses Vigilance
and has -1/-0
Sacrifice a Trilobite creature: Opabinia gains
Vigilance and +1/+0. This ability can only be
activated if the Era is not Cambrian. If the Era is Cambrian, you may sacrifice a Trilobite. If you do,
place a +1/+0 counter on Opabinia