Geosgaeno

Geosgaeno is a Geo-type Fiend in Final Fantasy X which appears very early on to threaten Tidus when he tries to find shelter in the ruins of a temple. After 3 turns, Tidus wisely decides to flee and gets away from the beast. Later on, once the party has gained control of the Airship, these ruins (identified as Baaj Temple) can be revisited and Tidus, now accompanied by Wakka and Rikku can attempt to defeat the boss and enter the chamber which houses the Fayth of the hidden Aeon, Anima.

Strategy
Geosgaeno attacks with Stone Punch, causing Petrification. Because the fight takes place underwater, your characters will instantly shatter, making them inoperable. In addition, Geosgaeno uses the ability KO Punch, instantly knocking one of your characters out. Therefore, it is advised to have armor with Stoneward or Stoneproof, as well as Death Ward or Death Proof. This monster also inhales one character occasionally. When this happens, all positive status effects such as Protect or Haste will be applied to Geosgaeno so long as the character is still contained within it. The character within it may Struggle or Defend. If the one inhaled does not Struggle, the next turn Geosgaeno gets, it will exhale, bringing them to 1 HP and knocking out the other two characters. If they do Struggle, Geosgaeno will exhale and only KO the one who was swallowed. One additional effect that Geosgaeno puts into play is that if a character is swallowed and it is defeated, it will cause 9,999 points of damage on all characters. This means that one should never defeat Geosgaeno if one character is swallowed.

A simple strategy is equipping a weapon with any elemental affinity (i.e. Firestrike) onto Tidus and use Quick Hit multiple times. Hastega is also a good option. Rikku can use Elemental Crystals and Wakka can use Elemental Slots. It has relatively low HP as well, so the battle should not be entirely too difficult. So long as one has Haste and Quick Hit, this boss will be simple enough.

Final Fantasy X-2

 * Georapella