*Author's note: Here is the poem once again. Still unsure about whose devotion this is? The answer is below the poem.
She awaits in a serene meadow.
My lover waits as she has waited for what feels like years.
I rush to her, running so fast I almost fly over those soft blades of grass.
We meet in the sun and embrace, kissing and making love like neither of us can understand.
I love her, and she loves me.
She kisses me harder, and I know this will be the last time we touch.
She wraps her arms around me, and gently bites my face.
I begin to stop feeling.
Her mandables grow wider and wider,
enveloping my face and swallowing it,
I feel peace.
I am at peace.
I love her.
She loves me.
Now we'll be together always.
I've given her my devotion.
I've given our young everything that I am.
So now I will sleep, and dream of our embrace.It was worth the wait
ANSWER: The creature consumed by all encompassing devotion is none other than the enigmatic Praying Mantis. However, the Black Widow is also a feasible answer, as it shares similar habits.