Perun, Perkunas, Perkons and other gods who aren't Thor

I don't really have anything off hand, but I do know that his relationship with his serpent is far more cordial than Thor's is. There's a sense of understanding that they need each other for balance and that they interact together to form the thunderstorms. The rain the storms makes feeds the rivers that is Veles/Velnias's domain. Also that he's strongest in whatever thunderstorm season is for the area that the person is in. For me, that would be summer, but in some places like the mid-west, I understand it starts more in spring.