Short answer: No because I think the average person doesn't deserve to die.

Long answer: Let's start by looking at what I have to gain from both of my two possible choices. Choice #1 is that I ignore the pizza and continue on my way. In this case nothing is gained or lost. Choice #2 is that I eat the slice of pizza. A single slice of pizza could vary in cost a lot but I'll use my local pizza place as reference. A medium cheese pizza is $5 and it's divided into 8 slices. $5/8 = 0.625, or 62.5 cents. So one of the things that I have to gain is 62.5 cents' worth of pizza. This isn't a very promising incentive on its own but we can also consider that the chance to randomly murder someone is an incentive on its own. If I hated other people and thought that they deserved to die this might be a good incentive but since I don't have power over who the pizza chooses as its victim, and I generally think that most people don't deserve death, I think that this actually works as a penalty rather than an incentive. And probably one worth more than 62.5 cents. Now if I wanted to be able to anonymously and untracably kill a single person of my choice, I might be able to accomplish this. I'm female, so all I would need is to seduce enough men to impregnate me, and hopefully not give me any STDs that might be passed to the child. I would birth the child at home after stockpiling medical supplies to deal with any possible complications. As soon as the baby was born I would quickly blindfold it and keep a blindfold on its eyes constantly. At some opportune time I would unblindfold my baby to expose its vision to only one target, so I would need to catch that target completely alone. I'd also need to create a vision cone for my baby so that it couldn't look back at me. Maybe spraypaint one of those post-surgery dog collars black and opaque. Then I would keep my latent murderer alive and blindfolded until enough time had passed to avoid correlation between this event and my target's death. Then I would feed my baby- now possibly toddler- the slice of pizza and commit one count of murder risk free! I haven't slept in 26 hours.