With the addition of the limited-time Kulve Taroth siege and the Caverns of El Dorado, at least two new rare pets have been added:
- The Tsuchinoko is a flat, snake-lizard like animal based on a real-life cryptid. You can find it in area 2 or 3 scuttling out of the tunnels Kulve Taroth creates along with the Callabros.
- The Golden Calappa is a much larger, golden variant of the bronze crabs that scuttle around on the floor. Seems like it will spawn where-ever the regular Bronze Calappa do.
The four trophy related pets are:
- Downy Crake (Snuggles for All): A fuzzy bird that rides on the back of Aptonoths or Apceros in the Ancient Forest of Wildspire Waste.
- Bristly Crake (Bristles for All): Only available in the Rotten Vale in a single location, start at Area 11 and move towards Vaal Hazak's lair. There is a blue pond with goldenfish that sometimes has the Piscine Researcher or First Wyverian; the Bristly Crake will be seen riding on the back of the Mosswine on the cliff above.
- Petricanths (A Living Fossil): Attainable in the game quite rarely, in a blue lake in the Rotten Vale past some rocks or camp 8 in Elder's Recess. A quick walk from Area 11's camp, and past the Bristly Crake spawn.
- Prism Hercudrome (Rainbow Bright): As the guide lists, this beetle only appears at dawn or dusk in the Ancient Forest or the Wildspire Waste. I caught it in the Waste, twice, on a tree overlooking Jyuratodus' regular spawn point. Also on dead tree in northeastern-most overlook in Ancient Forest.
Here's a decent video guide for visuals of where to find these four and what they look like.
In addition to these four, there are many forms of endemic life that have unique borders in the Hunter's Notes, designating them as rare variants. I'll list the ones I have after 110 hours of gameplay. Among these are:
- Pilot Hare, a pink variant of the regular Hare that spawns in the starting area of Wildspire Waste and also near a northern camp in the Ancient Forest
- Giant Vigorwasp, a huge Vigorwasp carrying a massive payload; this doesn't have a special border but seems to be fairly uncommon
- Forest Pteryx, an emerald Woodland Pteryx with a red crest rarely found on the trees in the Ancient Forest
- King Marlin, a giant marlin found off of the coast of the Ancient Forest where the Kestodon lounge.
- Emerald Helmcrab, a larger, green iron Helmcrab found on the floor of the Rotten Vale and Wildspire Waste
- Moonlight Gecko, a larger gecko from the Rotten Vale that frequently spawns near the Area 11 camp. Very noticeable, glows in the dark. Purple and blue spotted.
- Augurfly, an emerald Omenfly that seems to appear where-ever Omenflies can. I've caught them in the Ancient Forest, Wildspire Waste, and Rotten Vale.
- Wiggler Queen, a bright orange Wiggler from the Coral Highlands. Notes say they spawn at night. Hard to miss.
From digging around online, there also appears to be:
- Dapper Coralbird from the Coral Highlands (probably found among the regular kind)
- Phantom Flutterfly, a large prismatic yellow Flutterfly in the Ancient Forest.
- Grandfather Mantagrell, the large manta-ray type insect from the Coral Highlands near Sector 11 with the Grimalkynes
- Gold Hercudrome, found near Area 5 in the Wildspire Waste
I wouldn't be surprised if there were a rare variant of the Golden Helmcrabs either, considering every other Helmcrab location seems to have a rare variant.
Here is a video showing some of the rare pet locations across the Ancient Forest, Wildspire Waste, and Coral Highlands.