What is this?

You found a photo of some indistinct boney looking curvy horn/claw in your garden?

Do you know who the photographer is? If so, I think it would be a good idea to contact him or her and get some more information.

What does it feel like? Is it rock or something lighter?

Its a piece of rock found in mud.

looks like a fossilized animal horn, but it could be a tool.

Why didn't you give size, weight and several pictures/

About 2.5 inches long. feels like a rock.
http://imageshack.com/a/img833/6270/1nfn.jpg
http://imageshack.com/a/img23/1566/kca1.jpg
http://imageshack.com/a/img706/5443/pyaa.jpg
http://imageshack.com/a/img42/5636/1j7g.jpg
http://imageshack.com/a/img89/6263/o1rd.jpg
http://imageshack.com/a/img268/5937/i1h2.jpg
http://imageshack.com/a/img822/1342/pmm6.jpg

Unfortunately you're probably going to have to cross-section it to get an idea what the internal structure looks like.

It might also help to get a specific gravity on it to understand better what it might be made of. Is it Bone, Rock, Ivory, Enamel, Wood, etc...

Obviously it looks like a large tooth, but that could be pure coincidence. Orca teeth look like that. If it's a tooth, it's from a carnivorous animal, very large. Today that pretty much leaves Orcas and Sperm whales. If it's prehistoric, then it would be fossilized and no bone or tooth would remain (thus the specific gravity test).

Since you live in Manitoba it might be an old discarded Orca Tooth.

Hello! Second me it is a tooth..maybe a prehistorical tooth! last summer I participated in an archaeological dig and found a lot of teeth like this...

(???) http://2.bp.blogspot.com/-So-X1bxn8TU/UIhrMe6brYI/AAAAAAAAFQ4/M8xWlxXtP7E/s1600/2+cuernos+k+4.jpg