While I'm not a fan of Manowar, many of their songs have lyrics which stereotypical orc would sing.

Taken from “Into Glory Ride” album (1983).

I taste your blood as it showers from my blade.
I eat your heart, from evil it was made.
With heart filled hatred black blood runs through my veins.
I take your powers to the ancient ones who reign.

I conquer evil, let evil know my name.
Come forth ye wicked, know the gruesome pain.
I am the omen, the one that cannot die
I am the flame, hatred burns inside.

My strength is hatred, torment and pain, HATRED, HATRED.
With heart filled hatred black blood runs through my veins.

I crush your bones, I kill your face
I rip your flesh, I end the chase
You meet with terror, you draw the ace
I rule the world the rats that race.

My strength is hatred, torment and pain, HATRED, HATRED
With heart filled hatred black blood runs through my veins.

HATRED

The hero of the song fights the evil… by tormenting opponents and eating their hearts. So there is no need to change the text, as the perverted conception of Good and Evil suits Sauron's agenda perfectly.

MOGUM

Dashaub ghorI taste your blood as it showers from my blade.
I eat your heart, from evil it was made.
With heart filled hatred black blood runs through my veins.
I take your powers to the ancient ones who reign.

I conquer evil, let evil know my name.
Come forth ye wicked, know the gruesome pain.
I am the omen, the one that cannot die
I am the flame, hatred burns inside.

My strength is hatred, torment and pain, HATRED, HATRED.
With heart filled hatred black blood runs through my veins.

I crush your bones, I kill your face
I rip your flesh, I end the chase
You meet with terror, you draw the ace
I rule the world the rats that race.

My strength is hatred, torment and pain, HATRED, HATRED
With heart filled hatred black blood runs through my veins.

HATRED

This song is taken from album “Hail to England” (1984)

Hear what's written on the wind
We come to kill and kill again
Our arrows fall like hail
Trample on the dead
Ride through the gate of clouds
Stand on the open step

Run berserk spreading fear and pain
Black shield and weapons, black our chain
None can harm us not their fire, iron or steel
For we have the will to power
With power we will kill

[Chorus:]
Kill with power! Die! die! (2x)

To the war God Odin you will pray
And the curse of weapons shall remain
On the blood of all our fathers
On their weapons we now swear
To avenge, not lament
Give the false ones death

[Chorus]

In “The war god Odin” line the name “Odin” was dropped off, but as variant the whole phrase may be replaced with just name “Morgoth”. “Berserk” was translated with “hûr” (fierce, vigourous, fiery).

DOG BALSHA

Khlâr amash kulâ zurbaga zûlir
Daskât dogat agh dogat nokhar
Dakob pîl lûmpû oth nigz
Badh matalumir
Bam hûmum shustob as
Bin badzûrz prakumir

Khîg hûrarz bûsnug ufur agh hrizg
Mor lâzg agh yak, mor gai dakob
Narash pâsh rulak, nar ghâsh takob, onk ogh yazg
Zârzamarz dakbrus dirbum balu
Balsha dakdogub

[Chorus:]
Dog balsha! Ghur, ghur! (2x)

Gigorthub (Balmâgzu gothob / Morgothu)
Agh skurm yakob maug irnut
Ghorsha krankobûk dakob
Yaksha takob dak gazd(r)ad
Grûthat, narnîthat
Throgat gurz prakhûrz (Balmâgzu / Ashu)

[Chorus]