  We study the two-dimensional kagome-ice model derived from a pyrochlore
lattice with second- and third-neighbor interactions. The canted moments align
along the local $\langle 111 \rangle$ axes of the pyrochlore and respond to
both in-plane and out-of-plane external fields. We find that the combination of
further-neighbor interactions together with the external fields introduces a
rich phase diagram with different spin textures. Close to the phase boundaries,
metastable $\textit{"snake"}$ domains emerge with extremely long relaxation
time. Our kinetic Monte Carlo analysis of the magnetic-field quench process
from saturated state shows unusually slow dynamics. Despite that the interior
spins are almost frozen in snake domains, the spins on the edge are free to
fluctuate locally, leading to frequent creation and annihilation of
monopole-anti-monopole bound states. Once the domains are formed, these
excitations are localized and can hardly propagate due to the energy barrier of
snakes. The emergence of such snake domains may shed light on the experimental
observation of dipolar spin ice under tilted fields, and provide a new strategy
to manipulate both spin and charge textures in artificial spin ice.
