The shishi — the Chinese guardian lion — has protected the entrances of temples, palaces, and aristocratic homes in China for more than a thousand years. The Western term 'foo dog' (a corruption of 'Fo,' the Chinese transliteration of Buddha, with 'dog' a rough description of the creature) became standard in the English antiques trade and is the search term most collectors use today. Whatever they're called, the objects are always a matched pair: the male, with his paw resting on a decorative ball (representing sovereignty over the world), and the female, with her paw resting on a cub (representing nurturing of the next generation). Placing the male on the left and the female on the right, as viewed from inside the building looking out, is the traditional arrangement.

The material range is enormous. Porcelain foo dogs — especially in iron-red (coral red) and gilt, in Chinese export blue and white, or in Famille Rose enamels — are the most common form in Texas estates. Bronze pairs, often with a patinated or gilded finish and incised detail, reflect the traditional use of metal guardian lions at palace and temple gates. Cloisonné foo dogs combine the enamel technique with the guardian form. Jade and hardstone pairs (in white jade, celadon jade, or various colored stones) represent the luxury end of the market. Carved stone pairs in limestone or marble were made for garden use and appear often in Texas garden collections.

The period range is equally broad. Tang and Song dynasty examples exist in major museum collections. The most commonly encountered Texas estate examples date from the Qing dynasty (1644–1912) or the Republic period (1912–1949), with export-market examples produced for Western buyers from the 18th century onward. 20th-century decorative production in Hong Kong and mainland China supplies the majority of the decorative market.