  Typical magnetic skyrmion is a string of inverted magnetization within a
ferromagnet, protected by a sleeve of a vortex-like spin texture, such that its
cross-section carries a positive integer topological charge. Some magnets form
antiskyrmions, the antiparticle strings which carry a negative topological
charge instead. Here we demonstrate that topologically equivalent but purely
electric antiskyrmion can exist in a ferroelectric material as well. In
particular, our computer experiments reveal that the archetype ferroelectric,
barium titanate, can host antiskyrmions. The polarization pattern around their
cores reminds ring windings of decorative knots rather than the typical
magnetic antiskyrmion texture. We show that the antiskyrmion of barium titanate
has just 2-3 nm in diameter, a hexagonal cross-section, and an exotic
topological charge of minus two. We deduce that formation of antiskyrmions is
favored by a fortunate combination of the moderate anisotropy of the anharmonic
electric susceptibility and the characteristic anisotropy of the polarization
correlations in barium titanate crystals.
