I’ve always found fire based characters who’s hair turns into flames when they’re mad a very fun character design (looking at you Hades), but also very helpful in this case. One thing about Chompies is that they have one set expression as soon as they become fully formed beings. Their eyes are solid and unmoving and their heads are a hard shell that is extremely hard to crack.
Pretty much, Solaris can’t change his face, and when feeling angry, they have other ways of showing it. Although Solaris isn’t short tempered or hot headed by any means, she can get rather passionate when upset. Which is also where the little character in the corner comes in.

That is Juniper, a skunk/red panda hybrid (I was indecisive and couldn’t pick either one for her character, so both is good). She’s Solaris’ artist manager and takes care of the business side of things while Sol is the main event. Juniper is also the only one that actually knows they’re a deity, but she tries not to let that get in the way of their professional relationship. Which sometimes involves scolding them for almost setting the place on fire.