The Order of Drell is the second largest Order of Knights in Ailendamus behind the larger Order of the Hydra. The were founded in order to fight in Ailendamus' wetlands. Drell Knights specialize in aquatic combat and can fight underwater.
They wear armor that looks like glass and ride specialized horses. These steeds may be some type of kelpie-cross and are slower than typical warhorses.
The Order of Drell is first seen in Ch. 8.69 T when 18 Drell Knights challenge Lord Tyrion Veltras to single combat. He defeats them in succession.