It stops, sniffs to the left, then turns to the right and slithers behind the ribcage.
This is a medical robot, guided by a skilled surgeon and designed to get to places doctors are unable to reach without opening a patient up.
It is still only a prototype and has not yet been used on real patients – only in the lab.
But its designers, from OC Robotics in Bristol, are convinced that once ready and approved, it could help find and remove tumours.
The mechanical snake is one of several groundbreaking cancer technologies showcased at this week’s International Conference on Oncological Engineering at the University of Leeds.
Most of the devices are in very early trial stages, but Safia Danovi from Cancer Research UK says that innovation and research are extremely important in tackling the disease.