Uji is a stout black shark roughly one-and-a-half times the size of a Dekapon. It has red eyes, grey gill-slits, and a large mouth filled with barbed teeth (which it tends to lose when slain). It has a large dorsal fin and smaller pectoral and tail fins.
Uji has the inexplicable ability to move through the ground like it was water, which it uses to maximum effect when hunting. It is incredibly aggressive, not even trying to masquerade as a Kacheek when idle. It seems to feed on Patapons, presumably because it can devour them in a single gulp.
When hunting, Uji remains mostly below the ground, with only its dorsal fin giving away its position. When the Patapons provoke it by attacking or getting in range, it raises its head from the ground, roars, and approaches them. Once in range, Uji leaps out of the ground and lands mouth-first on an unlucky victim, swallowing it whole.
After catching a Patapon, Uji burrows underground and retreats. At this point, it moves more slowly-possibly because it is still digesting its prey, or because of the exertion of its jump. At this point, the Uji is extremely vulnerable to reprisal from the Patapons, not in the least due to its tendency to surface and become stunned after its fin is repeatedly attacked. If it does escape, it will move some distance away before turning around and preparing to attack again.
Ujis seem to prefer deserts, swampland and beaches, presumably because the soft ground is easier to move through. Strangely, they seem to dislike rain - after the endless downpour in Nyokiri Swamp is halted, the sharks are only seen when the skies are clear. This may be intended to avoid competition with Parcheeks, who are commonly seen on rainy days.
Although they are relatively small targets that attack quickly and instantly kill Patapons, Ujis are not especially dangerous if you keep calm and rational when they attack. They can only eat one Patapon at a time, after which they retreat, leaving them wide open for a counterattack. Furthermore, you'll usually only run into one per mission - unlike Parcheeks, which can appear in groups of three, but sometimes two Ujis might appear.
Uji WILL probably eat one of your Patapons before you can kill it, but as long as you retrieve the Cap, you won't lose a thing. At worst, Uji will devour your Hero (preventing his revival until you get back to Patapolis), but since you're in a hunting mission, it's not like you need the extra power.
The best strategy is to use a Toripon Hero and have Mahopons, Yumipons and/or Toripons as your squad (Megapons are not recommended since their forward attack movement might alert the shark). When you get in range with the Uji, play the Pon Pata or Don Don song PERFECTLY. Toripon Hero will always attack Uji regardless of command as long as you perfectly play the beats, while the other Patapons dodge. This way, Uji will obviously never reach your hero when devouring, while other Patapons will be safe as they get back to their position, provided that the Uji is already dead at that moment.
It is not necessary that the Toripon Hero be very strong enough to kill Uji in just 1 hit, just play the songs stated above perfectly.
If it catches a Patapon, Uji has to retreat, and it's extremely slow when it does. This is your cue to pummel it with your remaining Patapons. If you hit its fin enough times, Uji will jump out of the ground and land on its back, opening itself up for even more of a beating.
Once Uji can take no more, it'll collapse and give you a Gizaza Fang (Level 3 Fang), more than compensating for the temporary loss of a Patapon. Later on, it may also drop the occasional Nazozo Fang (Level 4).
In Patapon 3, it is best to deal with an Uji with an Uberhero with a ferocious and relentless Uberhero Mode, such as Tondenga's Giantdeth or Kibadda's Mad Charge. After the Uberhero Mode is executed, the Uji will most likely to die or reveal itself for more assault.
- Very rarely, in Patapon 3, a glitch occurs when an Uji is swimming, but it doesn't advance nor attack, leaving you to pass freely. This can happen if Uji is killed while he is swimming.
- Very rarely, in Patapon 3, a glitch also occurs when an Uji comes out of the ground and is dying, leaves to be lying down, but not dropping anything and the corpse stays there.