It’s not especially aggressive with anything too large to fit in its mouth, but once you’ve seen the yawn of an adult specimen it will quickly become clear that the choices are limited. The best tankmates are those inhabiting the bottom part of the tank, such as Fossorochromis rostratus or even Frontosa. Mbuna are not a good choice.
A male can be kept along with several females, but are territorial towards other males. Obviously, an enormous amount of space would be needed to house multiple males.