
Murray's color headcanon, by me.
I do believe that he got poisoned by his actual parents so they can get rid of him, before deciding to send him into the orphanage because they either weren't able to raise him, or his real parents... were bad.
I imagine that they tried poisoning him because they did not want him, but failed, they did do it, but *thankfully* murray did not get hurt by it, but got turned from normal hippo color, to pink.
I think that because of this he had mental problems with himself such as trust issues, and thinks that he wasn't worthy because of that day.
I imagine that he had a breakdown because of it and told them about it when they became older, they tried helping him regain his confidence and the trust in himself, and they actually succeed.
And then..murray becomes the muscle dude we love and adore, i imagine that he sometimes checks orphanages for kids with similar conditions to comfort them and give them candy and tell them that they're brave and they must continue because they are amazing no matter what occurs.