This is a jagged ambush bug, Phymata americana. These guys sit on flowers, and wait for butterflies or bees to visit. They capture them and inject them with poison, then suck the juices out.
That’s what they do. I know scientists frown on calling living things evil. But evil just seems to describe them well.
Thomas Eisner had an interesting story about these creatures in For the Love of Insects. It seems that a bite from one of these insects to the leg of a spider would kill the spider–unless the spider was able to remove its own leg, which some of them did. If it got rid of the leg that was bitten, the spider would live. If it did not, it would die.
Not a good choice to be given.