also for some synbranchus species....View attachment 1489983
https://en.wikipedia.org/wiki/Earthworm_eel
May I introduce you to the world of Chaudhuriidae? Also known as the earthworm or spineless eels. They are incredibly rare. However, they are very similar (and related) to spiny eels. I do not believe they've ever been recorded at 3" or more. That being said, they are fairly obscure. I'd say they would make good substitutes for even the smallest of spiny eels.
https://www.wetspottropicalfish.com/product/garo-khajuriai/
You can buy one species here, but don't rely on them being in stock.
Finally I see the thread actually making sense now..
Can see the resemblance, both are air breathers tooBetta unimaculata is a perfect substitute for dwarf snake heads (banned here in the us)
Pretty closely related tooBetta unimaculata is a perfect substitute for dwarf snake heads (banned here in the us)