A strange envoy from the "Far Outsiders," namely the Yuuzhan Vong race, reached out to the leader of the Vagaari Imperium, Miskara, within the Unexplored Territories, around 23 ABY. The Vagaari started integrating Yuuzhan Vong bio-technology as payment for their Vagaari support in the Yuuzhan Vong assault on the galaxy.
The introduction of the Yuuzhan Vong envoy occurred in The Unknown Regions, a 2010 sourcebook released by Wizards of the Coast for the Star Wars Roleplaying Game.