Myth - reproduced on the ground of folkloristic given: the fight of Perun against demoniac opponent (main - Żmij? Veles?, aerial dragons and crowd of smaller ghosts: biesy, sing. bies, czarty [ czart ], latawce[ latawiec ], porońce [poroniec] etc) stealing waters, cattle, divine partner of god (see: Perperuna), hiding before anger of Thunderlord under/in a man, horse, cow, tree, stone, at last in to water (a fish with red eyes). Perun is helped by płanetnicy (sing. płanetnik), chmurni-cy(-k), obłoczni-cy(-k) (Pl), stuh(-y), zduh(-y), stuhac(-e), zduhac(-e), vjetrogonj-e(-a), jedogonj-e(-a) (Serb) and, after to carriage names from demoniac enemy to the helper, zmaj(-e), zmej(-e) (Bulg) and żmij(-e) (Pl.) (spirits, living peoples and even animals with spirit or with body being raised to sky during storm) fighting with smok(-i) ("a dragon") (Pl.) zmej(-e) (Russ.), a?dah-a(-y) (SouthSlav. from Pers. A?i Dahaka), (ch)al-a(-y) (SouthSlav.).
Perun was represented with silver hairs and golden moustaches (Russ.), his weapon: stones, stone - arrows, their remainders according to folk beliefs are fulgurites and belemnites, and sometimes archaic tools, all they are called (in Poland): kamień piorunowy, kamień gromowy ("stone thunderbolt"), klin piorunowy ("wedge thunderbolt"), strzał a piorunowa ("arrow of thunderbolt"), piorunowiec, iskra pérunova ("spark of thunder"), palec diabla, palec czarta ("devil's finger") but also: God's finger, and even Mother of God finger (compare to: Lith.: "Berkun's finger" - sic!) - after that also a hammer and an axe. Thunderbolt stones are sometimes transferred back to skies (by wind or pł anetnik). Weapons of Perun protected before bad luck, bad powers, disease and thunder itself.
Perun's vegetable hypostasis was oak (about of what one mentioned higher), especially distinctive (the oldest, greatest, growing on a hill)- a space under - general place of worship and folding of sacrifices (with a bull, an ox, a ram, eggs); marked oaks stood on country borders - communities, these "stations" were visited during holidays of village late spring and summer (SouthSlav.) (compare to: Iupiter Quernus, see also: Perkunas). Perun is also connected with other plants: perunika, perin (Serb., Russ.).
Primary relations with almost identical Perkunas from Latvian mythology are difficult to explain. In Vedic religion this god is called Varuna.
Christianity replaced Perun by Saint Elijah the Thunderer.
Etymology
OldSlav. per-unъ ?Slav. god Perun, thunderbolt" < *per-oun-os ( Gr. keraunós "t.s."), "telling" name (making core of mythological group of ideas formed round conception of Lord of Thunder), describing distinctive act for this god: ?to fling a rock"(per-perun-a?); OldSlav. *pr-a-ti < *per-a-ti "to strike, to beat"; OldSlav. *pr-e-ti < *per-ti "to push, to press strongly"; Lith. per-ti ?to hit, to beat, to strike, to whip"; Trac. per(u) "rock"; Hett. peruna(?) "t. s., goddess of Peruna?".
Toponyms
Examples of toponyms named after Perun: Perun, Perunac, Perunovac, Perunika, Perunić
ka Glava, Peruni Vrh, Perunja Ves, Peruna Dubrava, Perunu?a, Peru?ice, Perudina, Perutovac (SouthSlav.), Prohn, Pronstorf (East Germany < Sorb.=Polab.; from Peron?).