Inflection curves (cyan) and cusp curves (red) plotted in the top panel over contours of the Jacobian tangential factor j_T(x) showing the tangential critical curves, and in the bottom panel over contours of the Jacobian radial factor j_R(x) showing the radial critical curves of the ellipsoidal NFW lens with eccentricity e = 0.9. Contours are plotted in both panels for κ_s from 0.25 to 1.25 in steps of 0.25 with κ_s = 1 marked black, and with the additional dashed-black umbilic κ_s ≈ 0.398 contours. The top panel includes the smallest κ_s = 0.125 contour; its radial counterpart is too small to be visible in the bottom panel. The dashed green κ_s ≈ 1.195 contour in the top panel marks the tangential-peanut transition parameter combination. The solid purple κ_s ≈ 0.432 contour in the bottom panel marks the radial-peanut transition parameter combination.