The Tesla anomaly functions much like an Electro anomaly and deals electric damage, with the difference is that the Tesla is mobile. In that sense, it's the Electro's equivalent of the Comet. It takes the appearance of a fast-moving ball of pure electricity. It can be said the Tesla is the evolved or greater form of an Electro. It's possible that a particularly large or intense Electro anomaly went undisturbed or built up a massive charge for an extensive amount of time and became mobile as a result, either to discharge its built up energy or to 'hunt' for targets or prey.
Unless one is equipped with a few electricity-absorbing artifacts and/or wearing a suit with high electrical protection, simply being scraped by this anomaly reduces the player's health to 10% and outright kills them if they get struck directly by it.
This anomaly does not spawn any kind of artifact.
Call of Pripyat
Thankfully, teslas are quite rare: only three of them appear overall in the entire game.
- The Anomalies from the Metro 2033 games look and behave in a vaguely similar way to the Tesla.
- Considering that Tesla anomalies only appear in Call of Pripyat, it can be assumed that they began as a result of the fourth large Emission seen at the end of Shadow of Chernobyl.