The Pelican

According to legend, in a time of famine a mother pelican would draw blood from her own chest and give the blood to her chicks.
Thus the pelican symbol in Christianity, also called pelican-in-her-piety, symbolizes the sacrifice of Christ on the cross (because he
gave his blood for others) as well as the Eucharist (because it represents Christ's blood and provides spiritual nourishment).

The legend of the pelican is an ancient one and had a few variations. It was adopted into Christianity by the 2nd century, when it
appears in the Physiologus,  a Christian adaptation of popular animal legends and symbols.

So Our Lord Jesus Christ says also through the prophet Isaiah:: "I have brought up children and exalted them, but they
have despised me' (Is 1:2). We struck God by serving the creature rather than the Creator. Therefore He deigned to
ascend the cross, and when His side was pierced, blood and water gushed forth unto our salvation and eternal life."

The legend became popular in Christian art and was taken up by many later writers, including Shakespeare:

"To his good friend thus wide, I'll ope my arms
And, like the kind, life-rendering pelican
Repast them with my blood." (Hamlet, 1616)

Relevant Bible Verses

"This is my blood of the covenant, which is poured out for many for the forgiveness of sins." (Matthew 26:28)
"Jesus said to them, 'I tell you the truth, unless you eat the flesh of the Son of Man and drink his blood, you have no life in you.
Whoever eats my flesh and drinks my blood has eternal life, and I will raise him up at the last day. For my flesh is real food and my
blood is real drink. Whoever eats my flesh and drinks my blood remains in me, and I in him." (John 6:53-56)