The Gelatinoid is the root cause of Wendell's Nightmare, and must be destroyed in order to free the old man from it. A small horde of Slimes chased Wendell through his nightmare, exhausting him. When the Slimes finally corner him, Alundra appears, at which point they merge together to form the Gelatinoid.
As a composite enemy, the Gelatinoid splits into smaller creatures, and then back into Slimes, albeit considerably more of them than the number that created it. Like all bosses, it shares Alundra's brief invincibility after taking damage.
First form (Large)
The initial large form of the Gelatinoid has no attacks as such, but does move towards Alundra with the intention of causing contact damage. This is especially hazardous immediately after damaging it.
After depleting this form's 40 hit points, it splits into four smaller versions of itself.
Second form (Small x4)
The smaller versions of the Gelatinoid are essentially identical to the larger version, apart from having fewer hit points and, obviously, being smaller. They retain the invincibility period in this form.
With 28 hit points each, the smaller Gelatinoids are more easily despatched than the larger version. It is possible to attack more than one of them at once, shortening the battle. Once defeated, each of them splits into four Slimes.
Third form (Slime x16)
Entirely identical to normal Slimes, these are a nuisance primarily by sheer quantity. It is possible, and indeed likely, that there will be several Slimes on the field at the same time as one or more of the smaller Gelatinoids.
In this form, each of which has the Slimes' usual 9 hit points, the invincibility period is lost. Once all sixteen Slimes are destroyed, the battle is won.
- Sprite sheet for Gelatinoid sprites