This video from Portugal is about a sword-grass moth caterpillar.
It was a sword-grass moth.
Wardens had smeared syrup on English oak trees to attract moths. If the night is not too cold, then moths will come to feed on the syrup. This February, one of the moths at the syrup turned out to be a sword-grass moth. A very rare species. It had been seen for the last time in the Netherlands in 2001; in Drenthe province, much further east.