Cellar Dweller
(1988)

30 years ago, famous cartoonist Colin Childress (Jeffrey Combs) draws a monster in his basement studio.  His drawings summon a real demon that kills a woman and then him.  The police think he killed the woman and then committed suicide.

30 years later, his mansion is now an artist colony.  Whitney (Debrah Farentino) is a young cartoonist working in his old basement studio.  Whitney is obsessed with Childress's work and replicates his drawings.  Several of the artists there don't consider her cartoons real art, and treat her badly.  She draws Childress's monster killing the others.  One by one, her drawings come true and they disappear, consumed by the monster.

The monster attacks Whitney.  She throws things at him and a bottle of white out lands on the drawing table, covering his image.  She realizes her drawings control him.  She draws each of the other artists defeating him and coming back.  They all return, uninjured and with no memory of events.  She decides to destroy every image of the monster.  However, she also burns the images of the artists defeating him.  As their images burn, they melt away and disappear again.  The monster returns, laughing as it devours Whitney.  

Thanks Joseph C!