Someone who is completely naive or innocent who you could never picture doing anything sexual. Usually refers to males. Not based on physical appearance.
"He's SUCH a baby penguin!!!"
"I know! Girls are too sexual for him..."
Someone who is naive in the ways of sex.
Kurt Hummel was a baby penguin until his boyfriend tapped that ass.
Someone who you cannot picture in a sexual way whatsoever (to the point you reject the existence of their genitalia), it could also mean someone who is avoids anything sexual and becomes overly uncomfortable and awkward if anything related to sex comes up.
This person will forever be in the friendzone.
This person is also generally male.
"We were making sexual innuendos all night but he didn't get any of them..."
"Probs because he doesn't know what sex is...he's such a baby penguin!"
"He always leaves the room if the word sex even enters a conversation...typical Baby Penguin..."
"Well, he probably doesn't even know what a vagina looks like..."
"I love corrupting Baby Penguins! :)"