Tail or Life?

Nihon Kanahebi | Japanese Grass Lizard

The Japanese Grass Lizard is a familiar lizard that often bask in the sun on stones to rise their body temperature.
When they are in danger, they detach their tails and run away while the enemy is distracted by their tails, a defensive measure called autotomy. After that, the tail is reproduced, but it requires a lot of energy, so the lizard don't want to do autotomy as much as possible.

The tail is detached where the pattern changes.

Japanese Grass Lizard (top) and Japanese Lizard (bottom)
The Japanese Grass Lizard has jagged scales and a longer tail than the Japanese Lizard.