\documentclass{standalone}

\usepackage{tikz}
\usepackage{shapes}

\begin{document}
\begin{tikzpicture}
  \grid{10}{10}{(-5,-5)}

  \staircaseV{blue}{(0,0)}

  \square{lightgray}{(-4,4)}
  \square{lightgray}{(-3,3)}
  \square{lightgray}{(-3,4)}
  \square{lightgray}{(-2,2)}
  \square{lightgray}{(-2,3)}
  \square{lightgray}{(-2,4)}
  \square{lightgray}{(-1,1)}
  \square{lightgray}{(-1,2)}
  \square{lightgray}{(-1,3)}
  \square{lightgray}{(-1,4)}
  
  \square{lightgray}{(1,4)}
  \square{lightgray}{(2,3)}
  \square{lightgray}{(2,4)}
  \square{lightgray}{(3,2)}
  \square{lightgray}{(3,3)}
  \square{lightgray}{(3,4)}
  \square{lightgray}{(4,1)}
  \square{lightgray}{(4,2)}
  \square{lightgray}{(4,3)}
  \square{lightgray}{(4,4)}
  
  \square{lightgray}{(1,-1)}
  \square{lightgray}{(2,-2)}
  \square{lightgray}{(2,-1)}
  \square{lightgray}{(3,-3)}
  \square{lightgray}{(3,-2)}
  \square{lightgray}{(3,-1)}
  \square{lightgray}{(4,-4)}
  \square{lightgray}{(4,-3)}
  \square{lightgray}{(4,-2)}
  \square{lightgray}{(4,-1)}


\end{tikzpicture}
\end{document}