The rhyme doesn't work...
Quick, identify the following animals as being dangerous corals or totally harmless (or nearly so) venomless or low toxicity rear fanged species... Ready? Stolen photos start now!
To make it even easier, some of them should have the nomenclature right on the photo and all of them are from the same website with the filename identifying the species... But you just use your rhyme and tell me which ones to freehandle. Just promise to pay for my medical bills in advance.
The only good advice which can be given for people to determine if a snake is potentially dangerous or not is...
IF YOU DON'T KNOW WHAT IT IS, LEAVE IT ALONE. Treat all unknown animals as being venomous until you are 100% totally certain this is not the case. Don't mumble some rhyme and then get yourself nailed by something dangerous... or mumble some rhyme, encourage others to mumble some idiotic rhyme and sit back as abberrent thayeri are decapitated by the hundreds.