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-wavelength 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 appears as a stable vortex–domain wall composite excitation and exhibits complex 2D dynamics at long times, while the vortices remain confined and the topological structure of a magnetic domain wall persists.

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• Domain walls
• Spinor Bose-Einstein condensates
• Solitons