It didn't.
Horns make a helmet, particularly a fighting helmet, immensely impractical. A strike would get caught on the horn instead of sliding off. Maybe cut through the helmet, or break the neck instantly.
The idea of horned helmets stems from horned figures in rock carvings, and have never been supported by any archeology. The rock carvings may well be of some religious nature, and not an actual picture of something that was real.
Answer
The reason why some traditional viking helmet have horns is a few depictions which is actually mounted with animal horns or some replicas. This may also due to their religious beliefs.
guess how use your brain and get lost
Vikings had a metal helmet with no horns on so any one that told you that they did they are wrong. The idea of the Vikings having horns on there Helmets came from the Victorians
helmet
The Minnesota NFL team is nicknamed the "Vikings". Think of the classic image of a Viking, with the classic horned helmet. The logo on the Vikings' helmets is supposed to look like those horns sticking out. Obviously, trying to do a 2-d drawing of the horns like that leaves a bit to be desired and one has to look at it with a little imagination.
It seems that many ancient Celts used horned helmets, also, Romans have depicted germanic peoples wearing them as well, there is a theory that these were only ceremonial. During the middle ages many Knights had horns of different shapes on their helmets. A horned viking helmet has never been found, but as Ian Malcolm says: Absence of proof is not proof of absence.
You don't...
guess how use your brain and get lost
A red viking helmet.... and if click on the hidden button for the viking helmet 4 times, you'll get the blue viking helmet, with a description saying- "Gadzooks! You've found the blue viking helmet! Incredible!"
They usually did have helmets in battle. Not helmets with horns because they weren't that foolish. A helmet with horns would make it easy for the enemy to grab the horns and drag the viking down and kill him/her (Yes her).
If you're reffering to the blue viking helmet, then i know. You have to find where the red viking helmet is hidden in the clothing catalog. Hit that once and then close it. Do it 2 more times. Then do it 1 more time. There you go! ;)
the viking helmet, it can be ANYWHERE IN THE CATOLOG! if you open in and close it 4 times you get the blue viking helmet
You cant get a 'Rainbow Viking Helmet', Reason = It doesnt exist
The viking helmet is always hidden in a different place.
It is very rare but I think you can get it by doing the following: In the catalogue for the costume trunk, go to the viking section where there is a girl penguin wearing a viking helmet. Click the helmet on the word 'viking'. Get the red helmet. Press the 'x', click the same helmet again, close it, click the helmet again, close it then click it again but don't press the 'x'. This time press the helmet on the girl penguin's head.
The Red Viking Helmet and If you click in the same spot where the Red Viking Helmet is there should Always be a Blue Viking Helmet, And if there is always a Blue one there is a red one
Vikings had a metal helmet with no horns on so any one that told you that they did they are wrong. The idea of the Vikings having horns on there Helmets came from the Victorians
The Viking helmetif you fiddle around, you will be able to find it really easily.it's the red viking helmet. there is also a blue viking helmet which you can get by finding the red one, then opening and closing the pop up cataloug with the red helmet in it. eventually the blue viking helmet will pop up and you can buy it for 1200 coins.there is also a gold viking helmet which you can get in the play called the viking opera. this one is actually cheaper than the blue viking helmet, with a cost of 1000 coins. i dont know how to get the gold helmet but i do know that it is in the costume trunk hidden somewhere.