Thanks for the words, y'all.
I'm learning to pay attention to reference pieces. I'm just glad that Rick did make full-body images of the kangaroos in the comics. Gave me something to look at.
I imagine that Arezzo will have some level of high hopes about meeting his father. If so, I don't see that ending well. Of course, then it's the question of if the jell-o anvil is canon.
Though Homer will be in for quite a surprise when he realizes that the kid is just as durable as he is.
And yes, Dayzee, Arin is a kangaroo, and yes, he's a male one. As my post stated, he eventually figured out how to keep track of Oliver. He's a mortal in Heaven, if you don't remember. The comic has shown four examples of people changing their form to suit their desires or needs when they get there.
Actually had the scenario for when Arin figures this out planned.
Macabre and Mirage are picking up Oliver from Arin's residence
Macabre: "Thank you for looking after him, Dad."
Mirage: "From the looks of things, he gave you a run for your money?"
Arin, exhausted: "Yes...I've dealt with energetic joeys before, but this kid is really something else."
Macabre: "He's quite the slippery little devil, is he not?"
Arin: "Frankly, I started thinking about getting me one of those baby carriers. Easier to keep track of him in one of those."
Mirage: "But, you're a kangaroo, right?"
Arin:
"Um, yes. Why is that relevant all of a sudden?"
Mirage: "Why don't you keep Oliver in a pouch?"
Arin:
"Mirage, I don't know how many kangaroos you've met in your travels, but only females have pouches. Males like me don't."
Mirage: "But, you're not a mortal anymore. Heaven removes limits."
Arin: "..."
Macabre: "All who are here are free to alter how they are, Dad."
Arin:
Mirage: "This should have been covered in Orientation. Did you forget that you could change your form however you like in any way?"
Arin: "..."
Arin looks down at his abdomen, and a pouch suddenly manifests
Arin, dumbfounded: "This. Changes. Everything."
Macabre: "And there we go."
Mirage: "Macabre, don't be surprised if we visit one day and your dad is some incomprehensible entity."