How Holy Motion animated The Secret Agent's 'hairy leg' in stop motion over live-action plates

Kleber Mendonça Filho's Oscar-nominated political thriller The Secret Agent (2025), set in Recife under Brazil's military dictatorship, includes a short stop-motion sequence of the perna cabeluda. This "hairy leg" urban legend was a coded way for journalists to write about the regime's violence. In a piece by Carlos Aguilar for Cartoon Brew, the filmmakers explained how the sequence was made.

Mendonça Filho first tried shooting an actor in a green suit and dropped the idea because it did not convince. He also chose stop motion over 3D CG on purpose. He wanted mechanical, physical movement rather than smoothness: a limb that looks independent and out of control, which he likened to the Tasmanian devil.

The job went to Holy Motion, the stop-motion studio in Arnhem, Netherlands, founded by Mascha Halberstad, director of the feature Oink. SFX propmaker Rolf te Booij built a puppet of about 30 centimetres, modelled on the life-size decomposing-leg prop seen in another scene of the film. Peter Mansfelt designed a skeleton that let the toes move separately, and he also served as director of photography. Animator Rosanne Janssens animated the leg against green screen in Dragonframe over three weeks.

The live action came first. In Brazil, Mendonça Filho laid 30 metres of track on the ground of a park so the camera ran at the height of the leg. Janssens followed that camera move by onion skinning in Dragonframe with the live-action plates underneath, and the stop-motion leg was composited into the footage. Where the leg physically attacks the actors, Mendonça Filho himself wore a green glove and worked a full-size prop on set. Halberstad said lighting was the trickiest part: the leg moves through a dark park, so the light has to move with it.

The workflow is now the first worked example on our Wiki pages for Dragonframe guide and reference layers and for onion skinning.