You Must Be Happy

{1}{c} Choose a creature you control then flip a
coin if it lands on head (YES) then give the
creature +1/+1 if it lands on tails (NO) then
give the card -1/-1.
If this cards ability is used again in the same turn
then it becomes a 25/75 coin flip Heads is 25%
and tails is 75% but the benefits and negatives
are doubled respectively.