Koma, Cosmos Serpent

This spell can't be countered.
At the beginning of each upkeep, create a 3/3
blue Serpent creature token named Koma's Coil.
Sacrifice another Serpent: Choose one —
•Tap target permanent. Its activated abilities
can't be activated this turn.
• Koma, Cosmos Serpent gains indestructible
until end of turn.