give birth to a big ol' litter of kittens

[IQU3838]

Hi,

I have a phrase that needs your help, thank you.

"She is gonna give birth to a big ol' litter of kittens when she see her boyfriedn messed up his pretty face."

I can roughly guess that the underlined part means "unhappy" or "angry" something like that, but am not quite sure what it exactly mean and why.

Can anyone help me? Thanks in advance

[BobK]

I've met the (informal) expression 'to have kittens' to mean 'to be extremely upset/angry'. The addition of a litter (the collective noun for a number of newborn animals) isn't idiomatic; it's just the speaker's new-coining to add emphasis.

b