Sea Dragon Leviathan

When a spell targets a creature you control,
deal 4 damage to the caster
A little under a thousand years ago, a Sea Dragon Leviathan Egg was taken by the Precursors and contained within the Disease Research Facility for testing, however, the parent Sea Dragon pursued the Precursors back to the facility and destroyed it,
resulting in the Kharaa Bacterium being released onto Planet 4546B, causing the Precursors to put the planet
into quarantine.