It was actually a male. A VERY obvious male once you got him out of water. Water really does make it all shrink.
BUT, he has passed since I posted this. He wedged himself under one of the heaters, and got burned when the heater turned on. He DID escape it, and I moved him to a 10-gallon tank by himself for a bit, but the burned skin turned white, and then developed an infection. I began to treat him, but just as I did, he passed away. I'm assuming since the top of his head was part of the burned area, the infection set in REALLY fast right on his brain. Just a bad combination overall.
However, there are now four discus total and four angelfish in that tank. Three platies (the newt ate one, but then I got a male sunset dalmation platy), seven otos, one giant male betta, and an L264 Sultan Pleco. I LOVE watching the otos school across the front of the tank though! THAT was an awesome addition!
And the sultan pleco has decided to rearrange the sand and gravel. So my aquascaping is in the process of being ruined. No worries, as long as he's happy.
The giant betta actually kinda bullies the angels and discus around. He doesn't tear them up or anything, but he'll flare and chase them sometimes. Even though he's a giant, he's somewhat small at only 3 inches total length (tail and all). Giants are supposed to be 3-4 inches BODY ONLY.
But everything is living peacefully in there. I've even tossed in some female shrimp, and they'll pop up now and then during feeding time to eat what the others can't fit in their bellies!
Oh, I forgot the assassin snails. I have found PLENTY of pond snail shells on the black sand, so I know they're doing good. And I keep finding their eggs everywhere too! So lord knows they're happy!