The Coelacanth appears in battle in groups of two or three and sometimes alongside Fire Antiques. It is the dark form of the Haken Büchse. The only time it appears in this form in the field is in the Middle 3 area, leaping back and forth along the lower platforms that lead to the South Entrance area.
Its normal attack is a jabbing attack on any targets in front of at melee range. Its most powerful Special Attack is Ultra Spin, in which it whirls for four hits of damage on any target in melee range with a strong knockdown effect. Heat Gas is a distance gaseous attack on one, while Volcanic Missile is a fiery distance attack with a chance of knockdown. Finally, it may use Sun Below on a single target from a slight distance to place them in Shining Body status.
The Coelacanth is definitely less of a challenge than its light Haken Büchse counterpart. It has low defense and HP and generally can easily be taken out in one or two turns at most. The only real attack to really watch out for is the four-hit Ultra Spin. Additionally, if it uses Sun Below on a character, it may be worthwhile to move them away so that it doesn't morph into the Haken Büchse . If Frederic or Polka need to do healing, just have them move to the area directly outside the field of shadow and heal from there.
- In the PlayStation 3 version of Eternal Sonata, the EXP gained for defeating a Coelacanth was slightly decreased, but its stats otherwise seem to be generally the same.