Tykos 30
From Halopedia, the Halo wiki
Tykos 30 is an organic tracking devise. It has a similar appearence to the yellow liquid "Blood Plasma". One Marine described to a man injected with the substance that they "can track ya to Mars". The Covenant were not aware of its use and were not able to track the substance.[1]
Sources
- ^ "We can track you. They can't"
