in the bible theres a famous verse about lions laying with lambs right? muslims sometimes call themselves lions, christians are lambs?

No, you are incorrect. There is no scripture that says the lion shall lay down with the lamb. Isaiah 11:6 is as close as you will find. Bear in mind the warning that Jesus gives the Apostles in Matthew 7:15-21. Pay attention to the animals mentioned in the passage.

both are not correct, but there will be peace

Isaiah 11:6-9.

Muslims can't even get along with each other, they are killing each other

As much as I would like seeing that I don't think so

Actually, that phrase is NOT found in the Bible.

What it actually says is: "The wolf also shall dwell with the lamb, and the leopard shall lie down with the kid; and the calf and the young lion and the fatling together; and a little child shall lead them."

I sometimes call myself a stallion, partly because of my stamina, but mostly because I'm so well hung.

jesus will perform Hajj (Pilgrimage) like Muslims

Prophet Mohammad صلى الله عليه وسلم said: "By Him in Whose Hand is my life (meaning I swear By Allah that), Son of Mary (Jesus) will make Talbiya (required declaration) for performing Hajj (Pilgrimage) or for Umrah or for both in the valley of Rawda." (Sahih Muslim)

Prophet Mohammad صلى الله عليه وسلم said: "Jesus, Son of Mary عليه السلام shall descend; then he will kill the pig and destroy the Cross; and a congregation will be held for him for the Prayer; and he will distribute so much wealth that people will be satiated with it; and he will abolish the Jizya (tribute tax on Christians & Jews) ; and he will camp at Rawda (a place at a distance 35 miles from Madina), and from there will go to perform Hajj or 'Umrah, or both." (Sahih Muslim).

I believe the verses you're looking for are:

Isaiah 11:6 "The wolf will live with the lamb, the leopard will lie down with the goat, the calf and the lion and the yearling together; and a little child will lead them."

and

Isaiah 65:25 "The wolf and the lamb shall feed together, and the lion shall eat straw like the bullock: and dust shall be the serpent's meat. They shall not hurt nor destroy in all my holy mountain, saith the LORD."

There is no such thing as the lion laying down with the lamb. It is a popular saying, that's all.

Both cannot be true.

Islam states Allah is one, He did not beget nor was he begotten

Christianity speaks of Jesus as the only begotten Son of the Father.