If one of my 2 ever did anything like that, their little rear ends would be blistered and they would learn the hard way how to respect and appreciate all animals - as well as everyone and everything in general.
And when it comes to punishing children, I'm not a fan of spanking, but one reason why I opted out of foster care when my family got involved with it, is because i like to reserve the right i have to beat my kids @$$ if they need it.
My children love animals and respect them. Maybe they have that upperhand because of how they have been raised in aquariums and zoo's since birth, and with apex predators right in their backyard, and the constant access to interaction, education and wildlife diversity they have. My daughter (6) is a little zoologist in the making, and takes her responsibilities as my "Jr. Keeper" very seriously, and is exceptionally attentive to our animal's health and well-being, and my son (4) is following in her footsteps. They don't play video games or watch weekend cartoons, they get their wet suits on and help me clean the lagoon, prep the diets for the following week, change filter pads and clean canisters, or scoop out the litter box for the cat, or go with me to the zoo where all my co-workers put them to work.
Sure they have the advantage of having that life and experience, and yea that's not the average life of most kids, but overall that doesnt mean that children who do not experice that cannot be taught the same ideals and values as mine are. Teaching children respect for all living things, responsibility for your choices and actions, and integrity is something that all parent's should make their number one priority.
I'm not a perfect parent and I will be the first to admit that while I glady swim with sharks, I will run away squealing from a butterfly, or jump on the couch and toss my son a shoe to smash a spider on the floor... which by the way rarely works with boys since they seem to enjoy catching animals like this and think its funny it freaks mom out so they have to chase you with it.
But regardless, my children would never do anything like that and its not because they are saints

faaaarr from it, but because they have been TAUGHT and SHOWN respect and responsibility and compassion.
So yea, the parents have a lot to answer for, and this kid needs to see a couselor immediately, bottom line.