You will find this Tockle in Laguna di Gondolia. There is a small cave you pass through to reach the central portion of the Laguna. That is where you will find the Tockle.
Whenever you first go to the Observatory, you will find some NPCs there. Speak with Aquila to get the quest, Go Fygger, where he wants you to find the missing Fygg, an item that is an offering to the Yggdrasil tree. Unfortunately, at the time you gain access to this area, you won’t be able to complete it, since the item you need is in the next area of the Altar of the Starry Skies, the Ruby Path of Doom.
Upon defeating the one boss there, you will receive the fygg in question, so bring it back for your reward, an item called the Benevolessence. The nice thing about this item is that using it in battle grants the same buff as Magic Barrier, which also stacks twice. This especially helps later on in the game, when you’re fighting enemies with powerful magic spells.