Incidentally, hiccups like this are the reason I didn't start with a crowd-funding; if you go into crowd-funding on something like this without having a huge portion of the work done beforehand, you're running a bigger risk of an uncompleted project and wasted money. Doesn't seem fair to anyone involved to impose that risk, so I'm holding off on the crowd-funding step until the entire manuscript has been written, edited, and laid out without art. That document will be a PDF available for free on the crowd-funding site, and the fundraising will be, first, to hire and pay some artists; and second, to produce and distribute hard copies and PDFs with art for distribution.
So, without further ado, I'll re-launch with a modest entry: another Featured Creature from the pages of the old Rules Cyclopedia, the manta ray!
This one presents kind of a conundrum. The RC monster entry for manta rays is biologically inaccurate, attributing to them behaviors (hiding on the sea floor) and natural abilities (poisonous stingers) they don't possess in real life. So, do I convert this monster as is and just call it a sting ray, or create an entirely new, and more accurate, entry for mantas and leave the sting rays for another time?
I split the difference with this entry. Since many of the RC version's stats are for an animal roughly the size of a real manta ray, I kept them intact. But I added in Species Traits closer to what real mantas are like.
One of the most fearsome-looking animals in the sea is also one of the most docile. Manta rays, sometimes called "devil fish" by land-dwellers because of their "horns," are gentle filter-feeders with little interest in or talent for violence. Often, they are as playful as dolphins or whales, and are known to breach the ocean's surface like those animals, too. Mantas give birth to live young, who are left to their own devices once emerging from the mother's oviduct.
Manta rays are also one of the smartest sea species in the world, and are renowned among fishes as keepers and teachers of knowledge ancient and new. Their reputation among fish is similar to that of whales among sea-dwelling mammals: wise, gentle, and honorable to a fault.
AT (Dam): 1 slam (1d3 [1d4])
Beginning HP: 7 
Habitat: Temperate, tropical, or sub-tropical oceans
- Brain Power: Manta rays have the largest brain-to-body mass ratio of any fish species, making them among the most intelligent animals in the sea. They get a +2 bonus on all lore checks involving complex problem-solving or tactical thinking.
- Cold Resistance: Mantas possess a mammal-like network of blood vessels in their brain called the retia mirabilia, which helps keep them warm. This grants them a +1 bonus on all saving throws to resist magical or natural cold.
- Growth Spurt: Mantas become Medium in SZ at 4 Total Levels
- Pressure Tolerance: Mantas can dive to depths of up to 2000 m (roughly 6500 ft) without suffering any MV penalties due to increased water pressure.
- Spatial Awareness: Like birds and most sea creatures, manta rays think and fight in 3 dimensions. They suffer no penalties in "aerial" combat against land-dwelling creatures who enter their natural habitat.
- Suitable Niches: Any.