Nautilus, Titan of the Depths

{3}{u}: Nautilus, Titan of the Depths gains Indestructible until the end of the turn.
{2}{u}: Create a colorless Artifact token named
Depth Charge with "{2}, Sacrifice this artifact:
Choose one-
This artifact deals 4 damage to target attacking creature without flying.
This artifact deals 2 damage to target creature
with flying.