Serperior is a primarily pale green, serpentine Pokémon. Its face and throat are white, while its back is dark green. Curled, mint-colored patterns extend into the white portion of its face, and it has narrow red eyes. In the lower jaw, two fangs are visible when its mouth is open. There are two pointed yellow extensions on the back of its head. Coiled, dark green extensions spread out from the sides of its lower neck, forming a curving pattern lower down the body. It has now completely lost the legs from its previous stages and now must slither about due to its new, serpentine form; however, just below its neck, it has two small leaf-like arms on either side of its body, which it usually keeps folded behind its back. It has curved yellow markings around its middle and several palmate leaves on its tail.
Serperior will only attack with full force against opponents that are unfazed by its piercing glare, which is said to be able to halt its foes' movements. It is capable of amplifying solar energy with its body.
Serperior evolves from Servine and is the final form of Snivy.
Ken Sugimori has said that Snivy, Servine, and Serperior are based on Western culture, specifically mentioning Lady Oscar from the manga series The Rose of Versailles as an inspiration. Serperior, Emboar, and Samurott's evolutionary lines are collectively based on Western, Chinese, and Japanese culture respectively, to represent the diversity of the Unova region.
The fact that Serperior amplifies sunlight in its body, as stated in its Pokédex entry, may be an allusion to King Louis XIV of France, who famously referred to himself as the "Sun King". Its white face may allude to the skin whitening fashion, mostly used by the European aristocracy in the 17th century. The way it keeps its tiny arms behind its back is a signal of dominance and authority. Its body markings resemble the acanthus leaf motifs popularized during the Renaissance. The dark green design on its chest seems to form a fleur-de-lis, a French insignia that is used on many European noble families' and nations' coat of arms. Along with its regal look, Serperior's ability to seize opponents with its piercing stare may be a reference to the basilisk, the king of serpents in European legend.
Serperior may be a combination of serpent, superior, and possibly warrior and emperor.
Jalorda may be a combination of 蛇 ja (snake) and lord.