But Heracles simply glowered so fiercely that Charon meekly conveyed him across the Styx. The greater challenge was Cerberus, who had razor teeth, three (or maybe fifty) heads, a venomous snake for a tail and another swarm of snakes growing out of his back. These lashed at Heracles while Cerberus lunged for a purchase on his throat. Fortunately, the hero was wearing his trusty lion's skin, which was impenetrable by anything short of a thunderbolt from Zeus. Heracles eventually choked Cerberus into submission and dragged him to Tiryns, where he received due credit for this final Labor.