Spark Mouse

Sacrifice this card: Search your library, hand,
and/or graveyard for a card named Shock
Mouse and put it on the battlefield. Activate
only on your turn and only if you have 4 or
more experience counters.
{r}: Put a shock counter on target creature,
creatures with Shock counters gain, "At the
beginning of combat on your turn, flip a coin
if the result is heads, this creature cannot attack
this turn."