Tholian starships were small starships of characteristic shape, utilized by the Tholian Assembly during the 23rd century. These vessels were armed with plasma torpedo-like weaponry. But their most powerful weapon was the so-called "Tholian web". This web was "weaved" by two or more Tholian vessels around an enemy ship, trapping it. The web could then be contracted, destroying the vessel inside.
In 2268, a Tholian vessel intercepted the USS Enterprise, demanding that it leave Tholian territory. At the request of First Officer Spock, Tholian Commander Loskene allowed the Enterprise additional time before they were required to withdraw to allow the Enterprise to rescue James T. Kirk from the interphased USS Defiant. The Enterprise crew was unable to rescue Kirk within the Tholian time limit and the Tholians opened fire, damaging the Enterprise. The Enterprise returned fire, inflicting damage on the Tholian vessel.
Soon after, a second Tholian vessel appeared, and the two ships began constructing a web in an attempt to trap the Enterprise. The Enterprise crew, fortunately, was able to recover Kirk and escape before they fell victim to the Tholian's web. (TOS: "The Tholian Web")
Ships of the class
The studio model for the Tholian ship was designed by Walter M. Jefferies and constructed in part by Denis Russell. wbm This model was the last new original design created for the series, and would later be redressed to represent the Aurora in "The Way to Eden". In fact, according to Star Trek Maps, due to the similarity it was believed by Starfleet that the Tholians were using modified Federation space cruisers as their starships.
For the 2006 remastered edition of "The Tholian Web", the Tholian vessels appeared much different from their initial appearance. Now more closely resembling the Tholian ships from Star Trek: Enterprise (episodes "Future Tense" and "In a Mirror, Darkly"), the TOS-R version featured an altered structure and lighted interior.