hello, i am part of the freedoom team, a project to create a free and open source game capable of running doom mods with completly free assets. you can read more about the project in the link below

 https://freedoom.github.io/

several of the pupular versions of the doom engine implement a supporting character, the helper dog. even thoug the doom engine is open source, several source ports have trouble getting into repositories of oss because they use the propietary dog sprite for the dog helper. the sprite we are looking for is something resembling this:

http://www.spriters-resource.com/resources/sheets/27/29100.png

the death frames can be replaced with the dog simply falling down, also the attack frames would need to have rotations

it would also be cool if the dog could have a techie vest, maybe like the one in this zombie

http://www.spriters-resource.com/resources/sheets/53/56133.png

you can look at the rest of our sprites here to get an idea of the style:

http://www.spriters-resource.com/pc_computer/freedoom/

thanks!