Mawloc

• WOTC Official Reminder Textofficial rules
  Fight — Each of those creatures deals damage equal to its power to the other.

• WWizards of the Coast2022-10-07
  Official Ruling
  A creature with ravenous gets its counters as it enters the battlefield. It doesn't enter the battlefield first and then get its counters. Any triggered ability that looks for a creature with a certain power or toughness entering the battlefield will see the counters when it checks to see if it should trigger.
• WWizards of the Coast2022-10-07
  Official Ruling
  If another permanent enters the battlefield as a copy of a creature with Ravenous, it will not enter with any counters from the ravenous ability.
• WWizards of the Coast2022-10-07
  Official Ruling
  The triggered ability that checks to see if X is 5 or greater refers to the value of X that was chosen as the spell was cast, which may be different from the number of counters it entered with if there are replacement effects involved. This is also true for any other ability that it has which refers to X and triggers when it enters the battlefield.
• WWizards of the Coast2022-10-07
  Official Ruling
  If a permanent spell with ravenous is copied, the copy will have the same value for X, and the token permanent that the spell becomes as it enters the battlefield will enter with X counters.
• WWizards of the Coast2022-10-07
  Official Ruling
  The creature Mawloc fights will be exiled instead of going to the graveyard if it would die on the same turn for any reason, not just because of the damage from fighting Mawloc. This is true even if Mawloc has left the battlefield by that time.

Rulings via Scryfall