bat rat 

someone who masturbates an awful lot.

Tom; where is Jim
Paddy; gone for another wank
Tom; he sure is a bat rat that is like his sixth today.

bat rat by Dellow June 30, 2005

Bat rat 

Cutesie name to call ur bestfriend

Hi best bat rat how’s it going

Bat rat by Bug lover September 12, 2021

rat bat 

The abbreviation for 'rat bastard', similar in context to mofo, or mother fucker. The s in bastard was originally included in the term, making 'rat bast', but the letter quickly quiesced because of the rhyme scheme rat bat offered. The phrase has a tendency to be overused by the uneducated.

(adj) mother fuck'n, fuck'n, mug'n
being dirty, scheming, or treacherous, trifle'n, cantankerous

(n) rat bastard, mother fucker, fucker, mug
of being no good, a scoundrel or shithead

What the hell is a rat bat?" "You ya stupid rat bat.

rat bat by Rat-BatMan November 25, 2010

batrat 

When you shoot a deer and it doesn’t die

Hunter: Yes! I shot him.
Tod: He didn’t die.
Hunter: Ugh. He’s a strong Batrat.

batrat by 123345567789 February 7, 2021