  We study the polygons governing the convex hull of a point set created by the
steps of $n$ independent two-dimensional random walkers. Each such walk
consists of $T$ discrete time steps, where $x$ and $y$ increments are i.i.d.
Gaussian. We analyze area $A$ and perimeter $L$ of the convex hulls. We obtain
probability densities for these two quantities over a large range of the
support by using a large-deviation approach allowing us to study densities
below $10^{-900}$. We find that the densities exhibit a universal scaling
behavior as a function of $A/T$ and $L/\sqrt{T}$, respectively. As in the case
of one walker ($n=1$), the densities follow Gaussian distributions for $L$ and
$\sqrt{A}$, respectively. We also obtained the rate functions for the area and
perimeter, rescaled with the scaling behavior of their maximum possible values,
and found limiting functions for $T \rightarrow \infty$, revealing that the
densities follow the large-deviation principle. These rate functions can be
described by a power law for $n \rightarrow \infty$ as found in the $n=1$ case.
We also investigated the behavior of the averages as a function of the number
of walks $n$ and found good agreement with the predicted behavior.
