History and specifics
Xanvia and Xoxxa were located in systems two days apart. In the 23rd century, the planets endured a generations-long war. Regions around Xanvia were littered with floating debris from destroyed warships.
In 2268, a cease fire and fragile peace began. As a neutral party, the Federation starship USS Enterprise was asked to deliver a token of peace from Xanvia to Xoxxa. En route, however, the oban was discovered to be a "sleeper" agent, a genetically engineered animal that would kill any Xoxxan lifeforms. James T. Kirk did his best to maintain the peace process despite the act of sabotage. (TOS - Star Trek: The Manga - Shinsei Shinsei comic: "Oban")