Here is the full list of all 13 WWE 2K BATTLEGROUNDS achievements.
Perform a pin successfully
Control the ram and feed your opponent to the alligator
Unlock the "Thunderstorm" Power Up
Perform 20 signature moves
Complete the WrestleMania event
Unlock the Everglades battleground
Win a Gauntlet match against 5 opponents or more
Fill the crowd bar
Win a Steel Cage match
Perform 20 taunts
Win a Royal Rumble match with 20 opponents
Pick up a motorcycle and a turnbuckle
Win a Royal Rumble match against 30 opponents in medium difficulty or higher