Text (UG+errata): Flip X coins; an opponent calls heads or tails. For each flip you win, put a Rabid Sheep token into play. Treat these tokens as 2/2 green creatures that count as Sheep. [Oracle 2009/07/08]
The tokens are of creature type "Rabid" and creature type "Sheep". [D'Angelo 2000/03/09]
You do not have to flip all the coins at once. [QAS 1998/09/09]
The opponent only calls heads or tails once, not once per coin. [Barclay 1998/08/12]
No, we don't know why Sheep are green. Maybe Seattle sheep graze near a nuclear power plant. [Barclay 1998/08/13]
Optional Rule: You do have to flip all the coins at once. Extra dexterity may be required. [Barclay 1998/08/12]
All tournament formats have banned cards from Unglued.