worried about a cat...bleh

Mom said that she was worried about some mean ol' stay cat that runs around the apartment complex. she said that when it first started comming around when we lived on the bottom floor, it would torment me and just sit there just out of my reach so i couldnt get it. (i just want to play with it.)

Mom says she hasnt seen it for a while and it just started showing up again looking like it lost alot of weight.

*mom here*

So this cat, i dont know if its a boy or a girl, used to swat at maraka when we went outside to go potty. maraka doesnt know many cats, she jus wants to play with anything. but this cat would just swipe at her and get her to go away. well kittie finally just started running when maraka showed up outside. kittie hasnt been seen all winter now, ive seen it running around and it looks.....emaciated. poor thing. i figured, stray cat has nails fend for self, untill this morning. this is not a ohhh touch me kittie. this is a come near me and i'll swipe and anything kittie. maraka and i went out about 7 this morning to potty, the kittie was sitting in the beauty bark and didnt move. i was able to touch it! maraka seemed skiddish as well as though she knew something was wrong. i feel as though i want to call someone but i cant pick kittie up or put it in the car or anything because b/f is deathly allergic to kitties.
what to do any suggestions?