Frostwalk Mage

Whenever Frostwalk Mage is tapped, add Frost Bite
to your spellbook.
———{line}{line}{line}{line}{line}{line}{line}{line}{line}
Frost Bite {u}{u}{u}
Sorcery-Cantrip
Tap target creature, then put a -1/-1 counter on all tapped creatures.