  In magnetic Weyl semimetals, fluctuations of the local magnetization may
generate gauge fields that couple to the chiral charge of emergent Weyl
fermions. Recent theoretical studies have proposed that the temporal and
spatial-dependent magnetization associated with propagating domain walls (DWs)
generates "pseudo" electric and magnetic fields that drive novel phenomena such
as a current of "real" charge. Here we report a key step in testing these
predictions: characterizing the propagation of DWs in the Weyl semimetal
Co3Sn2S2 using scanning magneto-optic Kerr microscopy. We observe an unexpected
deep minimum in the temperature dependence of the DW mobility, $\mu$,
indicating a crossover between two regimes of propagation. The nonmonotonic
$\mu(T)$ is evidence of a phase transition in the topology of the DW well below
the Curie temperature, in which the magnetization texture changes from
continuous rotation (elliptical wall) to a linear wall whose unidirectional
magnetization passes through zero at the wall center.
