The badger misses.
I am not going to give a miss chance to creatures grappling each other in the fog, although the penalty to hitting and damage stands.
Fang hits all six times, once really hard with a wing buffet for a total of 58 points of damage. The lizard has 5 HP remaining and does not lose Con.
Round 786
The lizard swallows Fang, inflicting 20-5=15 points of damage in the process. Fang has 90 HP remaining.
Fang claws and bites from inside the stomach for 24 points of damage. The lizard disappears. Fang is at 65N95E.
Round 787
A large, shadowy automaton made out of dull black metal, with a skeletal frame flies effortlessy into the arena to 50N100E20Z and waits. The automaton's exact position is difficult to tell due to its blending into the shadows.
The fog surrounding Fang and the badger disappears. A wave of negative energy flows over Fang and the badger. Fang withstands some of the energy (rolled 27 Fort save), but still takes 18 points of damage. The badger disappears. Fang has 72 HP remaining.