As a trophy nut, I wanted to get an opinion on whether other people wanted more options for their mounted beast heads. I know most are Undaunted stuff, and a few are very rare or crown store exclusive. I've made up a list of what we have vs. what I'd like. Input is welcome, maybe we can get Zos to notice and give some more variety.
We have, for normal wild animals: Kra'gh (Dreugh), Possesed Mantikora, Selene and Swarm Mother (spiders, and disappointingly identical), Chudan (Haj Mota), Troll King, Tremorscale (Duneripper), a wolf and a buck (crown store). I've also seen out in the world mounts for Durzogs, Echatares, bears, skeevers and nix hounds. Unfortunately those are, as far as I know, unobtainable.
For more unnatural beasts there are: Argonian Behemoth, Blood Spawn (Gargoyle), Chokethorn (Strangler), Domihaus (Minotaur), Infernal Guardian (Lurcher), Sellistrix (Lamia) and Balorgh (Hulking Werewolf). I'll add the Dwemer Sentinel of Rkugamz (Centurion) and Engine Guardian (Spider) here as well.
Daedra have a lot: Bogdan (Daedric Titan), Earthgore Amalgam (Iron Atronach), Foundation Stone Atronach, Grothdarr (Flesh Atronach), Iceheart (Frost Atronarch), Warden Dusk (Grievous Twilight), Malubeth (Harvester), Maw of the Infernal (Daedroth), Shadowrend (Clannfear), Spawn of Mephala (Spider Daedra), Stormfist (Storm Atronarch), Illambris Twins (Dremora), Velidreth (Hoarvor Daedra) and Ra kotu (Air Atronach).
Then there are a few with properly unique models: Assembly General, Blackheart, Hiath, Molag Kena, Nerien'eth, Rakkhat, St. Olms, Scalecaller, Thurvokun, Valkyn Skoria, Vykosa and Z'Maja.

This still leaves a lot of creatures with no decapitated representation. For some of the smaller ones, you could even make them taxidermied models, such as skeevers or crabs. Just something more to put in our trophy rooms other than the single most impressive thing we killed in a particular dungeon (and sometimes it's not even that. Swarm Mother? Really?).