>>58275525I think an interesting idea that could be done as well is a sea snake Seviper, sea snakes have a paddle like tail that sorta looks like Seviper's blade if squint, plus Water/Poison is a relatively rare type too and Water and Poison combo together really well.
Sea snakes also have the whole silent killer thing going for them due to their poison being not only extremely dangerous, but their bites are almost painless.