Looks like a cacodemon/beholder.
Also that black/orange crab monster reminds me of a flash game I've played before.

And could someone tell me where Ecco is supposed to be? Or something related to the game.

Made some changes regarding the artist, please do correct me if they prove incorrect.

TO Athal
Ecco is a Dolphin in a Sega Genesis game. He is in the pier bouncing a Ball with a L on it.

Katamari top right. Gunstar Heroes weapons on the "Massive Damage" sign far left. A tiny Megaman to the left of the Mushroom Kingdom area. I don't see Sonic, but I do see Green Hill, so changing tag to refer to the game unless someone can point out the character. Is definitely a cacodemon; so tagged.

@DoctorVisigoth: Sonic is there. He's standing on an arch in Green Hill.

I think I see Subzero near that row of houses.

Master Chief is kicking ass under the Brain Age balloon guy.

Dear lord, it's perfect.

Guardianmio said:
TO Athal
Ecco is a Dolphin in a Sega Genesis game. He is in the pier bouncing a Ball with a L on it.

I wasn't asking what Ecco is, but thank you for pointing out where he is. :)

Man, it's like Reboot Gone Wild.

Oh fantastic! Those are nice big photos of the original at last. Thanks um. :)

Holy shit, kudos to whoever tagged this

I updated Puma (Guitaru Man) it was listed as just Guitaru Man.

loco roco bouncing next to the parappa the rapper stage, cloud's out in front of the castle, and the ape's from ape escape are poking their head's out of the pipes next to him along with the rabites and mushbooms around the castle (from secret of mana)lara croft's standing and waving behind the van next to the tetris stack.... ummm... any more anyone can point out?

Umm... is that a baby cactuar I see below pinky and Clyde?

this is my mousemat!

Why does this come up on a search for Overman King Gainer? I can't see him anywhere on it.

I don't see Mr. Driller