I found this at a flea market in a box of kitchen tools but it looks more like a woodworking or leather tool.  The blade is stamped USM in a circle.  Looks like the handle was originally painted black but most kitchen tools I've seen were green.  The teeth are sharp.  The end looks like it is to pry something and is slightly curved.

Could be leather working, USM is sometimes United Shoe Manufacturing Co.

Hello, Lewill2 . You are right, leather working , or, upholstery. A similar tool is still offered by C S Osborne, No. 121 Tack & Staple Remover. Regards, lou

 Sellens shows a very similar tool labeled tack puller on page 468  of his book.

Those type are sometimes referred to as a sawtooth tack puller.

Yep.  Tack puller.  I had the experience of using one of those during my brief (yay!) experience as a last stapler in a boot factory.  When the foreman told me, at the end of two weeks, that the guy out on sick leave was coming back, and they were letting me go, it took all my self control not to dance out of there.  I'm just not cut out for production line work.  I went back to collecting unemployment while looking for work, and my net pay went up!

For those not familiar with the shoe world, the last is the foot-shaped mold around which a shoe gets built.  I'd get the uppers, all sewed up, in a cart with the matching wooden lasts.  Steps: put last into upper; set the last on the stapling* machine (a hole in the top of the last mated with a peg on the machine), orienting it so the heel faced the machine; tug the upper firmly onto the last; shove the mechanism forward; check that the two tacks the machine had just driven were through the upper properly and firmly into the last; curse if they weren't, and use the tack puller, just like the picture above, to pull the tacks, and repeat the process.  And repeat the process.  And repeat...I was going out at lunch and napping in the car, because the work was so deadly.

I suppose this would have some applications outside shoemaking, but the tack pullers used by furniture upholsterers are probably more flexibly useful; there's more angle between puller and handle.  So far, the best tack puller I've found is a C.S. Osborne product, from a yard/estate/something sale.  But even the funkier such pullers are pretty nifty for tacks and small nails.
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*It was called a stapling machine, but it was actually a bradding machine, see description above.