A species controlling a strategically vital stretch of space, whose baffling negotiating style of mirroring whoever they address was decoded by Captain Pike in 2259.
The R'ongovians hold territory between the Federation, the Klingon Empire and the Romulans, which makes an alliance with them highly valuable. They travel in a ship driven by a solar sail. They appear in the Strange New Worlds episode Spock Amok.
During talks at Starbase 1 the delegation behaves erratically. They are aggressive with the blunt Tellarites, coldly logical with Spock and hostile to Admiral April's team. Their mood seems to swing from meeting to meeting, and the negotiations stall.
Pike works out that the R'ongovians adopt the manner of each party in order to understand it, and that they want the same in return. He argues their side of the case and sets out honestly why they might refuse the Federation. They are satisfied and leave flying the Federation flag from their sail.