After you’ve defeated the Griffin and finished the first Blacksmith Blues side quest, you’ll get access to a ton of new recipes. One of them is Drakeslayer’s Bracelets. Chances are, you’ll have most of its materials at this point sans the Gelatinous Mass. Here’s where to find Gelatinous Mass in Final Fantasy XVI.
Where to find Gelatinous Mass in Final Fantasy 16
The Gelatinous Mass is only dropped by a hunt monster called the Flan Prince. On the board, it’ll be called the “Muddy Murder” as scouts weren’t sure what it was nor what it looked like. You can find it lurking deep in Hawk’s Cry Cliff. Remember that you can't find marks with no wanted poster up, so wait until after you get Titan's powers.
How to beat the Flan Prince in FF16
Flan Prince uses all types of magic in its arsenal, though I find its physical attacks more difficult to dodge. So, wait until it casts magic (even if it’s Dualcast) and dodge at the right moment. There’s a window to get a couple of attacks in after that. Use Phoenix or Ifrit’s movement ability to get close.
If Flan Prince uses that Hammer move, get as far away from it as possible if you’re not confident in your dodging abilities. That move’s really quick and has insane range. Make sure you have a full set of Potions with you as well. It’s much, much tougher compared to Severian and the other B-rank marks.
You can only subjugate the Flan Prince once, so you’ll only get one Gelatinous Mass per run. If you attempt the hunt again on new game plus, you’ll get another.
For more help with Final Fantasy XVI, take a look at Best Eikon Abilities Tier List – Final Fantasy 16 and FF16 Clive Build – Best Abilities for Clive here at Pro Game Guides.