I'm hoping there is. I'm working on 100 summons with Yami Yugi and I'm almost at 50 summons. That animation is really awesome. Besides, it would only be fair if Slither got one when they gave ond to Ra...
You get a Ra/Slifer playmat for summoning them 100 times. (Flip/Special or Normal). I did it with a Flip Deck with "Gonogo" which you can get by the card trader and Mystic Box. Gonogo an Ra/Slifer must have 0 Attack.