There are several types.
Negro Chilhuacle Chiles have a very mild fruity flavour with some anise tones. They are considered by some cooks to be the tastiest chile, and are highly desired, so they are expensive.
They are shaped like a very small bell pepper, 3 to 4 inches (7 1/2 to 10 cm long), and 2.5 to 3.5 inches (6 to 9 cm) wide at the top. They have shiny, thin skin and ripen from green to dark olive green to very dark brown, almost black.
They are grown in the Oaxaca region of Mexico, particularly in the La Cañada area.
They are used to make Oaxacan black mole sauces.
Rojo Chilhuacle Chiles have medium heat to their taste.
They are shaped like a very small bell pepper, 3 to 4 inches (7 1/2 to 10 cm long), and 1.5 to 2 inches (3 1/2 to 5 cm) wide at the top. The skin ripens from green to maroon or mahogany.
They are grown in the Oaxaca region of Mexico, where they are used in “mole colorado.”
Amarillo Chilhuacle Chiles have a somewhat tart, sharp taste with moderate heat to it.
They are 2 to 3 inches (5 to 7 1/2 cm) long, and 1 1/2 inches ( 3 1/2 cm) across at the top. The bottom tapers to a point.
When ripe, they will be a yellowish red or dark amber.
They are used in “mole amarillo” (yellow mole), though Costeño Amarillo Chiles seem to be more usual.
Note: Some dried Güero Chiles are referred to as “Chilhuacle Amarillo.”
Chile onza amarillo
These are small, yellow, hot chiles grown in Sierra de Juarez in Mexico.
The word “Chilhuacle” comes from huacal/guacal, which is a wooden crate.