I'll start with the background. Though the background is completely black and has the little Pipe going on in the left side of the image, it looks amazing with the characters of the image.
The character of the image has been drawn perfectly, in fact I cannot find any mistake in the character. The figure on which the character is on, has also been drawn and colored to perfection. The light neon Sky Blue glow gleaming from it's eyes looks amazing.
The character's hand's/claws about to rip it's kill, the Killer expression and the teeth with the tongue coming out of it looking ready to devour it's prey completely.
The text placed below, the color which is cyan Sky-Blue I presume? Has been put in perfectly.
Overall a job well done, and I look forward to seeing more of your works.
Everything from the expressions to the technique is well done! This is one of those exceptional Invader Zim fan pictures that actually displays quality. Well done!
The luminous glow of GIR's eyes just adds to the amazingness