Dejaren, a Serosian isomorphic projection.
An isomorphic projection (or isomorph) is a virtual construct similar to a hologram, but more advanced.
The Serosians utilize sophisticated isomorphic projections as laborers aboard their ships. One example was Dejaren, an HD25 Isomorphic Projection. (VOY: "Revulsion")
Kurros of the Think Tank used an isomorphic projection of himself to communicate with potential clients about their vessels. The projection was sophisticated enough to taste beverages. In 2375, he appeared on the USS Voyager to offer a solution to their "Hazari paradox". Captain Kathryn Janeway later evicted him from the ship by remodulating Voyager's shields to a phase variant frequency. (VOY: "Think Tank")