A list of creatures that can do the most damage in a reasonable pvp scenario in 2.10. Things like vulnerability res, armor, sheilds, distraction, Rend, etc are excluded since they vary based on the opponent.
1. Indominus Rex & Erlidominus: 20,505
Max level, Max attack boost, Revenge cloak on revenge, APR/Rampage with crit
2 Indominus gen 2: 19,140
Max level, Max attack boost, 50% ferocity, (mutual fury) Cloak, APR with crit
3. Indotaurus: 18,231
Max level, Max attack boost, Revenge Taunting Cloak on revenge or Pesky Alert while threatened, Cleansing Rampage with crit
4. Sonorasaurus: 15,381
Max level, Max attack boost, 50% vulnerability (taunting vunerability) another 50% vulnerability (counter attack) Devastation with crit
5. Entelolania: 14,355
Max Level, Max attack boost, 50% ferocity or 50% vulnerability, devastation with crit
6. Tenontorex: 12,990
Max level, Max attack boost, 50% vulnerability, DSR with crit
7. Testacornibus: 11,278
Max level, Max attack boost, 50% vulnerability, Devastation with crit
8. Trykosaurus: 10,938
Max level, Max attack boost, 50% vulnerability, DSR with crit
9. Hadros Lux: 9,228
Max level, Max attack boost, 50% vulnerability, Rampage with crit
10. Mortem Rex: 9,115
Max level, Max attack boost, Fierce rampage with crit
Most Rend damage possible in pvp
Andrewtodon: 12,306
50% vulnerability, Rending Takedown with crit against a creature with the most health possible 10,939