here. How does "Lion" shape up as a Poul Anderson-related theme?
(i) A young time traveller confronts a lion in "The Little Monster."
(ii) Other time travellers have an annual rendezvous point at the Inn of the Golden Lion. See here.
(iii) Poul and Karen Anderson's Gratillonius must track down a dangerous animal that turns out to be an escaped lion.
(iv) Gratillonius, a Mithraist, attends temples where Time is represented by a figure with a lion's head.
(v) Ivanhoans have leonine manes and fur.
(vi) Anderson describes a vivid mural of the Last Judgment in which the Father's face is half leonine. See here.
Anything else? We know of lions in works by related authors but here I am focusing specifically on Anderson.