\leadsto from right to left

(Remark: Please be sure to check out Heiko's extended/improved solution as well.)

Here's a solution that builds on and refines Christian Hupfer's suggestion. The two new macros -- called \flowsfroma and \flowsfromb in the following code -- produce very similar, but not identical, left-pointing squigglies: The first macro performs a rotation of 180 degrees; the second performs a reflection around a centered vertical axis.

\documentclass{article}
\usepackage{amssymb}  % for "\leadsto" macro
\usepackage{graphicx} % for "\rotatebox" and "\reflectbox" macros
\newcommand\flowsfroma{\mathrel{\vcenter{\hbox{\rotatebox{180}{$\leadsto$}}}}}
\newcommand\flowsfromb{\mathrel{\reflectbox{$\leadsto$}}}

\begin{document}
$u \leadsto v$

$v \flowsfroma u$

$v \flowsfromb u$
\end{document}

Your symbol looks similar to the one of stix package, hence you could use \leftsquigarrow:

\documentclass{article}
\usepackage{amsmath, amssymb}
\usepackage{stix}
\begin{document}
\[
\leadsto \quad \leftsquigarrow
\]
\end{document}

Otherwise, look at The Comprehensive LATEX Symbol List.

Extended version to Mico's solution:

• Math style is respected.
• \mathsurround is set to zero (\m@th) to avoid additional horizontal space if \mathsurround is not zero.
• \leadsto is a symbol, whose horizontal line segment (or the arrow) lies on the math axis. Therefore, the rotation origin is put on the math axis to avoid a vertical displacement of the symbol.

Full example:

\documentclass{article}
\usepackage{amssymb}
\usepackage{graphicx}

\makeatletter
\newcommand*{\flowsfroma}{%
  \mathrel{\mathpalette\math@point@reflection\leadsto}%
}
% Point reflection at point (width/2, math axis).
% Package graphicx is required.
\newcommand*{\math@point@reflection}[2]{%
  % #1: math style
  % #2: math symbol
  \begingroup
    % Height of box 0 is math axis
    \setbox0=\hbox{$#1\vcenter{}$}%
    \rotatebox[y=\ht0]{180}{$#1#2\m@th$}%
  \endgroup
}

\newcommand*{\flowsfromb}{%
  \mathrel{\mathpalette\math@reflect@box\leadsto}%
}
% Reflection at the y-axis.
% Package graphics is required.
\newcommand*{\math@reflect@box}[2]{%
  % #1: math style
  % #2: math symbol
  \reflectbox{$#1#2\m@th$}%
}
\makeatother

% Test part
\usepackage{xcolor}
\newcommand*{\TestAux}[2][\textstyle]{%
  \sbox0{$#1u#2v$}%
  \leavevmode
  \rlap{\textcolor{green!50!white}{%
    $#1\vcenter{\hrule height .05pt depth .05pt width\wd0}$%
  }}%
  \copy0 %
}
\newcommand*{\Test}[1]{%
  \TestAux[\textstyle]{#1} %
  \TestAux[\scriptstyle]{#1} %
  \TestAux[\scriptscriptstyle]{#1}\par
}

\begin{document}
\Test\leadsto
\Test\flowsfroma
\Test\flowsfromb
\end{document}

The thin light green lines mark the math axis.