  The retraction of an impacting droplet on a non-wetting substrate is often
associated with the formation of a Worthington jet, which is fed by the
retracting liquid. A non-Newtonian rheology of the liquid is known to affect
the retraction of the impacting droplet. Here we present a novel phenomenon
related to the impact of viscoelastic droplets on non-wettable substrates. We
reveal that the viscoelasticity of the liquid results in an
\emph{elastocapillary} regime in the stretching Worthington jet, distinguished
by a pinned contact line and a slender jet that does not detach from the
droplet. We identify the impact conditions, in the Weber number -- Deborah
number phase space, for observing these \emph{elastocapillary} Worthington
jets. Such jets exhibit an effectively nearly linear (in time) variation of the
strain rate. Upon further extension, the jet exhibits beads-on-a-string
structures, characteristic of the \emph{elastocapillary} thinning of slender
viscoelastic liquid filaments. The \emph{elastocapillary} Worthington jet is
not only relevant for a droplet impact on a solid substrate scenario, but can
also be expected in other configurations where a Worthington jet is observed
for viscoelastic liquids, such as drop impact on a liquid pool and bubble
bursting at an interface.
