Green’s Dictionary of Slang

mulligrubber n.

[mulligan n. (2) + grubber n.2 ]

(US) a tramp, a vagrant.

[US]Daily Trib. (Bismarck, ND) 12 Apr. 2/2: In their [i.e. waiters] places he got a gang of scattermouches and mulligrubbers that didn’t know bean soup from charlotte russe.