Ratt

Defender, deathtouch
When you cast this spell, copy it once, except the
copy isn't legendary.
{b}{b}, {t}: Ratt deals 1 damage to target creature
with power 3 or less.
{b}{b}, {t}: Put a corrosion counter on target
artifact or creature.
Activated abilities of permanents with corrosion counters on them can't be activated.