  We investigate the dynamical stability and real time dynamics of the
two-types of ferrodark solitons (FDSs) which occur as topological magnetic
domain walls in the easy-plane phase of a quasi-two-dimensional (2D)
ferromagnetic spin-1 Bose-Einstein condensate. The type-I FDS has positive
inertial mass and exhibits a single dynamical instability that generates in
plane spin winding, causing polar-core spin vortex dipoles. The positive
inertial mass leads to the elastic oscillations of the soliton under transverse
perturbations. The type-II FDS has negative inertial mass and exhibits a snake
instability and a spin-twist instability, with the latter involving the
generation of out of plane spin winding. Distinct from the normal dynamics of
negative mass solitons under long wave length transverse perturbations, the
snake instability does not lead to the type-II FDS breaking down. Instead,
segments of the type-II FDS convert to type-I and mass vortex dipoles are
produced. The resulting hybridized-chain of the two soliton types and vortices
exhibits complex 2D soliton dynamics at long times while the vortices remain
confined and the topological structure of a magnetic domain wall is preserved.
