Avroci, Endless Avarice

The Commander tax doesn't apply to this creature.
Lifelink
Whenever another vampire comes under your control, vampirecall 2(Look at the top 2 cards of your library. You may reveal a vampire creature card from among them and put it into your hand. Then put the rest on the bottom of your library in any order.)
Whenever another vampire comes under your control, tap a land you control, it does not untap during your next untap step.