Name:Renegade Doppelganger
ManaCost:1 U
Types:Creature Shapeshifter
PT:0/1
# Make SVars for granting abilities and triggers on clones distinct to avoid SVars getting overwritten when cloning a clone
T:Mode$ ChangesZone | Origin$ Any | Destination$ Battlefield | ValidCard$ Creature.Other+YouCtrl | TriggerZones$ Battlefield | OptionalDecider$ You | Execute$ RDCopy | TriggerDescription$ Whenever another creature enters the battlefield under your control, you may have CARDNAME become a copy of that creature until end of turn. (If it does, it loses this ability for the rest of the turn.)
SVar:RDCopy:AB$ Clone | Cost$ 0 | Defined$ TriggeredCard | Duration$ UntilEndOfTurn
SVar:Picture:http://www.wizards.com/global/images/magic/general/renegade_doppelganger.jpg
Oracle:Whenever another creature enters the battlefield under your control, you may have Renegade Doppelganger become a copy of that creature until end of turn. (If it does, it loses this ability for the rest of the turn.)