Many images are avaliable of Nack the Weasel [Also known as Fang the Sniper] as a boss in the Sonic X-Treme game. Each boss in the game was meant to be created out of Polygons with a free roaming field, an extension of NiGHTS boss levels. This is the best image avaliable of the 3D momdel, which doesn't look too bad for an early Saturn game.

The article notes this as Nack ducking to miss Sonic's Spin Slash attack. You'll notice several little items flying around the arena throughout these shots, and unfortunately they are unidentified.

Nack and Sonic closing into the actual arena. This is one of the better shots to show how much larger Nack is towards the Sonic sprite. The only thought would be that Eggman somehow made him grow, similar to MagiKoopa in Yoshi's Island.

Nack has fallen over dead on the left side of the screen, while the flying objects still hover around the arena. Note the HUD in the game, looking very BETA-ish with no real decent positioning and largely oversized.

Sonic seems to be walking around aimlessly, waiting to do something, most likely needing to grab that stone in the middle of the field.

Sonic, still wandering around the main arena aimlessly.

The best shot at the diamond. What are they, exactly? They're almost like a thinner time stone from Sonic CD, bnut certainly don't look like a Chaos Emerald. Notice the huge amount of rings surrounding it? It's almost like there is an endless supply.

Sonic, jumping high around the arena. Note the click icon and how it just doesn't fit with the HUD font? Probably just a filler tile.

A Zoomed in shot of Sonic just running around.

One of the more interesting shots, as it shows Nack attacking. Sonic has taken a hit with rings flying everywhere, and a low polygon explosion coming from what we assume is Nacks gun. Also notice how the playing field is quite large, and seems to copy itself over and over, perhaps Nack jumped from panel to panel to do a different attack, like Crash Bandicoot bosses or the Sonic 3D Blast final boss.