Walker, who’s from Alabama, was just five years old when this picture was taken.
It has been shared thousands of times by people all over the world.
His mum says she hopes this heartwrenching picture can raise awareness about the condition that killed Walker’s twin brother, Willis.
Willis died in his mum’s womb at 24 weeks by twin to twin transfusion syndrome (TTTS)
This is a disease of the placenta and causes it to contain abnormal blood vessels which connect the umbilical cords. Sometimes one twin may have a share too small to provide the nutrients to grow or even survive.
Speaking to the Huffington Post, his mum believes Walker has a really special connection to his brother and Walker agrees:
“He watches over me all the time. He died because of TTTS but I love him”
Now Walker is years old and each year his mum posts the same picture on their social media page Walker and Willis Walk to Fight TTTS
This year their walk will take place on March 11th – just over 10 years since little Willis died.
