We present pairwise emergent event horizons in a transition layer between type-I and type-II Weyl semimetals (WSMs). The Hawking temperature defined by a novel surface gravity at the horizon may be measurable. On the type-II WSM side, i.e., inside the horizons, the motion of the quasiparticles may be chaotic after a critical surface as they are governed by an effective inverted oscillator potential induced by the mismatch between the type-I and type-II Weyl nodes. In a relevant lattice model, we calculate out of time ordered correlators (OTOCs) of the quasiparticles. Inside the horizons, the OTOCs may fast scramble with a quantum Lyapunov exponent and after the Ehrenfest time the scrambling is saturated, which confirm the quantum chaotic behavior. Additionally, we find an extra quantum chaos in the lattice model which can not be described by the effective theory at the Weyl nodes.