Nonpareil and Rare bird

Nonpareil noun - Someone of such unequaled perfection as to deserve imitation.

Rare bird and nonpareil are semantically related. In some cases you can use "Rare bird" instead a noun "Nonpareil".

Rare bird noun - A rare or unique person.

Nonpareil and rare bird are semantically related. Sometimes you can use "Nonpareil" instead a noun phrase "Rare bird".