"El Cucuy" is the 5th episode of the supernatural drama television series Grimm of season 3 and the 49th overall, which premiered on November 29, 2013, on the cable network NBC.
Two weeks ago, a man named Andres Venegas (Garrett Hammond) is attacked in a gas station by two robbers, who severely wound him.
Nick and Hank (Russell Hornsby) find that they robbed a store so they head there where a man named David Florez (Manny Montana) yells at them for not doing their job.
While at dinner with Juliette, Monroe (Silas Weir Mitchell) and Rosalee (Bree Turner), Nick deduces that Bolton is a Höllentier, as he showed no fear of him.
El Cucuy kills Bolton and shifts to its human form, revealing itself to be Ms. Garcia, who senses that Nick is a Grimm.
Last year's 'La Llorona' episode got special promotion around Halloween, and that Mexican legend was one of the best standalone stories of the second season.
'El Cucuy' doesn't have much significance to the larger arc of the show—except for the very brief interludes with Adalind's first ultrasound and Renard receiving video evidence of the baby—but what makes it so fun is how differently the case plays out when compared to the regular structure.
For Grimm Season 3 Episode 5 justice is best served by El Cucuy, a nomadic, old lady roaming the world listening to the pleas of the disenfranchised.
You can't really deny that El Cucuy's victims were all raging dickbags who kind of deserved what they got, but at the same time, society tends to frown upon a vigilante.