The opening quote; "On many a dark night people would see her walking along the riverbank and crying for her children."; is from the myth of "La Llorona - the Weeping Woman".
Based on a legend in parts of Mexico, southwest United States, and Puerto Rico. Though several versions of the legend of "La Llorona" exist, the basis is that a woman named Maria drowns her children in order to be with a man she loved dearly. The man would not have her, therefore devastating her. Not taking "no" for an answer, she drowns herself in a lake in Mexico. When she reaches Heaven, she is challenged about the whereabouts of her children. Not being able to meet the challenge, she was unable to enter the afterlife, and is doomed to forever search for her children on Earth. Unable to find them, she is heard weeping, hence giving her the name "La Llorona". or "The Weeping Woman". Some variations of the story state that Maria will kidnap children who resemble her own, and others put her as a "nursery bogey", as a threat to disobedient children. Witnesses who claim to see La Llorona always claim to see her on the banks and shores of rivers, lakes, and oceans in Mexico. Some versions of the legend warn that hearing her wails would portend imminent death, similar to the legend of the banshee in parts of Ireland.
Elizabeth Tulloch's mother is of Spanish heritage and Elizabeth herself was raised in Spain, Uruguay, and Argentina in a bi-lingual household (Spanish and English).
The first episode of Grimm to be rated TV-PG. Most (and all since the pilot) are rated TV-14.
"Balam" comes from the Yucatec for "jaguar," from the creature of Mexican folklore; it is the second wesen name taken from a Native American language (the first being "coyotl" earlier this season) and the third whose name is lifted wholesale from an existing mythology (but only the second who is wesen, the other being La Llorona, in this episode). The balam of Mexican folklore are supernatural jaguars that protect the land and people, separated into Iqi-Balam (Moon Jaguar), Balam-Agab (Night Jaguar), Balam-Quitze (Smiling Jaguar), and Mahu-Catah (Famous Name).