Here it is finally: the Solar Doggy!
He always wags his tail happily: the more light there is, the more often he will do it.
And even when there is almost no light it keeps wagging; in that case very occasionally.
Not a Battery Eater
Working on a solar cell, he does not need any batteries. But because – like the Battery Eaters – he is very energy efficient, he is close friends with them!