I can’t find any edition of The Faerie Queene that uses the modern spelling “ouroboros” exactly. If you still want a faithful Spenser sentence that uses a variant referring to the serpent biting its tail, here is the relevant line from Book I, Canto XI, stanza 11 (as printed in many editions, spelling preserved):

“His fatall ympes linkt with yeeldinge gyves,
Which like an ouroborus did his taile embrace.”