Spherimorph is a Gel-type fiend from Final Fantasy X, encountered in the Macalania Woods. After completing the trek through the woodland trails, Auron remembers something from his journey with Braska and Jecht, and hacks his way through an overgrown side path. Down the new path is a spring, the water used to create spheres. With no warning, the Spherimorph attacks the party.
Appearing as an amorphous sphere of liquid, the Spherimorph is resistant to physical attacks and absorbs magic of all elements except one that is determined randomly. Hitting the Spherimorph with its elemental weakness will cause it change its elemental weakness with Elemental Shift. Because the element is randomly determined from the four main elements (it is never Holy), it can end up weak to the same element it was before. Its current elemental weakness can be discerned from its counterattacks that use a spell of the opposite element.
On its turn, Spherimorph will transform into a pillar and stomp a party member, dealing moderate damage. Once its HP has been halved it may flatten out and use Press, which halves the party's HP and is unaffected by Protect.
Spherimorph responds with different counterattacks in different situations. When hit for any damage of the element Spherimorph is currently weak against, or when hit for special damage of any element that Spherimorph is currently under the corresponding Nul status for, Spherimorph responds with Elemental Shift. When hit with physical or non-elemental special damage, or elemental magical damage from an aeon, Spherimorph responds with the spell of the element opposite to its weakness, targeting a single character. When hit with magical damage from party members, Scan, or non-weak and non-Nulled elemental special damage, Spherimorph responds with the same spell but targeting the whole party. Spherimorph's whole-party elemental spells are about 40% stronger than its single-target spells.
When hit with a reflected spell Spherimorph does not follow its usual counter pattern, but repeats whichever counterattack was used last. If it has not yet used any counterattacks, it will not counter reflected spells. If Spherimorph is hit by a character's counterattack, it will not counter-counterattack, but on future reflected spells will act as if it did.
The best strategy is to have one party member attack physically, wait for the enemy to counter with a spell, then have Lulu attack with the opposing spell (such as if Spherimorph counters with Blizzard, Lulu should follow with Firaga). Aeons of the right element, or ones that have learned appropriate spells, can be summoned for one turn and then dismissed if necessary. As always, beating it with an Overkill nets double AP, and the easiest way to do this is with an aeon Overdrive.
Yuna can cast her Nul-Spells to protect the party from Spherimorph's magic attacks, and Rikku's mixes can also be used for this purpose. Valefor is good for the battle because its Energy Ray does not run the risk of healing the creature, and she can cast black magic.
If the party has a Poison Fang, it can be used on Spherimorph. It will initially deal about 2000 damage and the Poison will do exactly 600 damage each time Spherimorph takes a turn. Poison Fangs can be stolen from the wasps nearby as a rare steal. Poison will not trigger Spherimorph to counter. Although Spherimorph has a high resistance to Poison, the Poison Fang will inflict poison 100% of the time. This strategy is extremely helpful if playing the game without the Sphere Grid.
The Spherimorph appears as a boss in several Final Fantasy X dungeons, and as a boss in the Ultima Nightmare Dungeon. In all its incarnations it fights much as in X, changing its elemental affinities when struck with its current weakness, and counterattacking any attack it is not weak to with a tier-two elemental spell corresponding to its current weakness. In addition to the Fire-Ice-Water-Lightning spells it had in X, it is also able to cast Aerora and Bio, but only the former four elements are swapped as elemental weaknesses.
Spherimorph is a compound word of "sphere" and "morph." Sphere has its roots in the Greek language, as "σφαίρα," pronounced "sphaira," and morph also originates from Greek, as "μορφή," pronounced "morphee," and means shape. Therefore, Spherimorph means "that, which has the shape of a sphere."
Its Japanese name is "Sphere Manager," referring to being born from the same water used to create spheres.