Small wedge-shaped ships of the territorial Tholians, able to work in pairs to spin an energy web around another vessel.
Tholian vessels were small, wedge-shaped ships flown by the reclusive and fiercely territorial Tholians. Working together, they could spin a web of energy around another ship, a tactic that could trap and destroy a far larger vessel.
In The Tholian Web, Commander Loskene's ships began enclosing the Enterprise while it tried to recover Kirk, who had been lost aboard the USS Defiant as it slipped out of normal space. Tholian ships had earlier encountered Earth vessels in Enterprise episodes such as Future Tense, and in In a Mirror, Darkly the Tholians of the mirror universe drew the Defiant into their own century.