"Bicho" is primarily a noun in Spanish.
/b'itʃo/
In the Spanish language, "bicho" commonly refers to small creatures such as insects or bugs. In some contexts, especially in colloquial speech, it can also refer to a strange person or a peculiar situation. The word is used frequently in both oral and written contexts, although it tends to appear more often in casual conversations.
Look at that bug in the garden!
No puedo creer lo que dijo ese bicho en la reunión.
I can’t believe what that weird guy said in the meeting.
Siempre hay un bicho que molesta en cada fiesta.
"Bicho" is often used in various idiomatic expressions, especially in informal settings. Below are some examples:
Don’t be a weirdo, join us.
Bicho sin cabeza
He was so confused that he looked like a headless bug.
El bicho del miedo
Don’t let the fear bug hold you back.
Bicho malo
The term "bicho" likely originates from the Latin word "beccius," which referred to a small living organism. Over time, it evolved in the Spanish language to encompass various meanings pertaining primarily to small creatures.