Box of Fireworks
Instructions: Rez the box and click it. Sit back and enjoy =)
The fireworks last a short while, so save it for when your pets are close to mating. The actual bonus-reset timer is random and uncontrollable, so there's no way of knowing when it will reset...so always try to time your fireworks as close to when they mate as possible. In theory, the fireworks could last as long as 2-4 hours, buuuuut...you're rarely that lucky =P
Each use of the fireworks increases its potential potency. The bonus-range begins at 18-24 and increases to as high as +30-40 (well beyond the practical cap...your evolution chances will be amazing, but the bonus applied to mutation is very small beyond +25). As with the bonus, the display itself increases in size with each use, with a grand finale at the end! =)
It's multiple use - I think about 10 or so. The box will delete itself once all charges are expended.