I am a hoarder, but trophies are pretty useless ATM other than for decoration (which destroys my fps) so I just keep them all in a chest which takes up valuable storage space.
I feel like they should be useable somehow, and here's my idea for something. Feel free to suggest other uses!
Once you defeat a boss, you should be able to sacrifice the trophies of the denizens of that biome for some sort of useful reward at the boss altar.
I.e. after eikthyr you can sacrifice boar and deer trophies at the alter, after the elder you can sacrifice troll and greydwarf trophies by burning them in the pyre.
As for the reward I'm not too sure, but I lean towards something that's not necessarily combat related and consumable to you can use it situationally.
My idea so far is rune stones, which have varying buff times depending on the value of the trophy. Such as a minor rune stone for greydwarf, runestone for greydwarf brutes and shamans, and major runestone for trolls.
A meadows runestone could provide something like increased foraging potential, providing a chance to get more berries/thistles/mushrooms from each source.
A black forest rune stone could perhaps provide better night time vision.
A swamp runestone could reduce the debuff from being wet.
Etc.
Perhaps minor rune stones could have a time of 2 minutes, regular runestones 5 minutes, and major rune stones 10 minutes.
Anywho let me know what you think in the comments! I just feel like this game needs a bit more magical enhancement type items and trophies seem like they should be useful for more than just decoration and a few crafting items.
Source: https://www.reddit.com/r/valheim/comments/n7sk0r/trophies_are_rather_useless_and_space_consuming/