noun
cat's sideways walk with arched back
Describes the defensive or playful posture where a cat arches its back, fluffs its tail, and hops or steps sideways, often in response to a perceived threat or during play. The term is colloquial and may be used humorously.
猫がやんのかステップでこっちに近づいてきた。
The cat approached me with that sideways arched-back walk.
動画で猫のやんのかステップがバズっていた
A video of a cat doing the 'yannoka step' was going viral.