Does anybody know if there are any spells in which i can turn into a creature(wolf,bear,ect).or as a vampire to be able to transmorm into mist,bat,wolf,ect.

None exist as yet to my knowledge, but what with the Werewolf scripting of Bloodmoon, it may be possible; it certainly is worth looking into. Perhaps some experienced scripter could take a look at this and say 'yes' or 'no?'

although i'm not one of the most experienced here i do have something to say.
i read that it is possible to change to a werewolf whenever you want, that is only after you've finished the werewolf quests.
as for other forms i don't think its possible. i've never actually encountert someone who has a spell or artifact that would allow you to change form

Any mods that have something similar?

Not at will- at night. The transformation occurs after nine o'clock every night.

There is an artifact that allows voluntary transformation- the Ring of Hircine. When equipped, the ring causes te player to change into werewolf form for 24 hours. The ring is on Tharsten Heart-Fang. You can get after he attacks you in the Mortrag Glacier, Inner Ring. if you're a werewolf, be sure to wait out your hours, transform to human form, get thr ring off his body, and then go back to werewolf form to face Hircine and Karstaag.

NPC transformation MUST be possible- Tharsten heart-Fang and the Werefolf ice statues both transform into werewolves. I don't think other forms are possible. If you use the script basics from thatm I'm sure you can make a transformation scriot for your idea.

Get "Scripted Spellcasting" if you have P.C. It's a mod that lets you transform into everything you mentioned (and a lot more) through spellcasting. By far, my favorite mod ever. Get it at Morrowind Summit. (www.rpgplanet.com/morrowind)

Just to be clear, I was referring to the mist/bat/wolf/bear animal things, not werewolf or vampire. It's great just flying around as a cliff racer.

Woah man i just got that mod after reading this and thats cool. You can turn into cliff racers and slaughterfish.

actually, it is quite possible to turn into a Werewolf at will any time you want, without a mod. by completing the Bloodmoon quests, i got the Ring of Hircine. simply equip this ring, at any time (yes ANY time, any place)on any character (except vampires i think), and you will become a werewolf for 9 hours. just dont use it in towns, because if anyone sees you transform, your screwed.

With out mod the only semi controlable transformation possible is the werewolf.

Actually i finally found a mod which lets you transform into different creatures(such as bears,cliffracers,bats,and more).I think it's called scripted spells by CORTEX.

DESCRIPTION
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Transform into creatures that can be seen in 3rd person view.

Steal spells from enemies minds.

Add explosive damage to your attacks.

Create walls of fire and animated bones.

Game balanced: Great care has been taken to ensure spells cost enough magicka
for their power. Transformations disable hand held weapon use and most spellcasting.
Wall spells require strategy to be effective. Stealing spells is a crime unless they
attacked you first.

This mod adds new spells created through scripting and new npc's who sell them.

That mod sound cool. I think i might download it my self.

it does indeed sound cool, where can i download it?

Go to morrowind summit to download just about any mod including this one