Testament of Joseph (recension A) speaks of the Messiah as a "Lamb."
Testament of Joseph 19 (A) in H. C. Kee (trans.), "Testaments of the Twelve Patriarchs," The Old Testament Pseudepigrapha, ed. James H. Charlesworth, 2 vols. (New York: Yale University Press, 1983), 1:824-25
1 “Listen, my children, concerning the dream that I saw. 2 Twelve stags were grazing at a certain place; nine were scattered over the whole earth, and likewise also the three.
3 And as I looked, the three stags became three lambs; they cried out to the Lord, and the Lord led them into a fertile, well-watered place. He led them out of darkness into light. 4 And there they cried out to the Lord until the nine stags were gathered to him, and they all became like twelve sheep. After a short time they multiplied and became many herds. 5 Later as I was looking, twelve bulls were nursing from one cow, who furnished a sea of milk. 6 The twelve herds and the innumerable herds drank from it. And the horns of the fourth bull ascended to heaven and became as a rampart for the herds. And from between the two horns there sprouted forth yet another horn. 7 And I saw a heifer which surrounded them twelve times and which became to perfection an aide to the bulls.
And I saw in the midst of the horns a certain virgin wearing a multicolored stole; from her came forth a lamb. Rushing from the left were all sorts of wild animals and reptiles, and the lamb conquered them.
Because of him the bull rejoiced and the cow and the stags were also glad with them.
These things must take place in their appropriate time.
And you, my children, honor Levi and Judah, because from them shall arise the salvation of Israel.
For my kingdom shall have an end among you, like an orchard guard who disappears after the summer.