The Onos swallows its victim whole and slowly digests him, gaining health (Changed to speed in combat) as the marine is consumed. The Marine can only be freed if the Onos is killed.
- Damage: 3 health per second (classic), Two health per second and one armor (combat)
- Rate of fire: 0.50 per second
- Energy cost: 20% (classic) 45% (Combat)