Can you find themed pets in the forest part of the lost grove? Or are they only in the caves? I've been walking around the LG forest part for a long time, and never encountered a themed, even with using a perfume. Are they just extremely rare, or am I looking in the wrong place?

Generally speaking themed pets in the LG are extremely rare, even when using a perfume. The perfumes work differently in the LG than in fest zones as you may use a perfume and never see a themed, but they build on each other as I understand it so by increasing your chances with each one used until you encounter a themed. Also, releasing pets helps with the percentage (or it did, not sure if that has changed, been a while since I've traversed the LG to be honest). As for the WOL themes those are drops or from the candy hearts. Hope that helps.

They are located in every part of the LG but the ones avalables in the caves and outside are not the same so if you are looking for a specific themme it may be good to check what the themme is bassed off before searching, by exemple a Tree Moss Zolnixi would only spawn in the forest area and not in the cave. They are very rare even with a perfume however if you run out of encounter on this perfume the odds of you finding somthing increass at the next one, from experiences on average you get 1 themmed by perfume but the RNG deffinitively play a part in that. ^-^

Edit :
Releassing pets increass your odds to find eggs, not themmed, the odds of said egg to be themmed seem to be higher then the normal encounter, however unlike their adult/adolescent counterparts an egg only have the minimal amount of wild stat no matter the amount of tp it have.

Ooh, thanks for the help!