SOLVED. A book about a boy whose name started with a J possessed by a lion. [s]

[Mattie]

When I was younger, around the time I was in elementary, I read this very interesting book that had a huge impact on my young mind. It had to have been published before 2010.

It was about a boy with a younger brother. The protagonist had a name that started with J (maybe Jackson, or Joey, or Jonas. Something like that.) because he and his younger brother Jamie had their mom/parents always call them her/their "little j's" or "my j's".

I think the parents were divorced and they have to drop off the boys at the others house every once in a while. The main boy was amazing at drawing. All I remember is that they ended up going to the zoo and meeting a tiger. The big brother becomes obsessed with tigers after making eye contact with the tiger at the zoo, and often had hallucinations or something that the tiger could speak with him. He was obsessed with drawing tiger eyes or collecting pictures of tigers or something. I suppose he was so invested in this that it made his little brother Jamie upset or jealous, and one day Jamie took the journal. My memory fogs up when I try to remember what happened. The protag probably ended up in trouble for getting angry at Jamie for taking it, because Jamie burned it or something. Jamie just wanted his old brother back.

I think that big bro and Jamie were to have a new sister. Jenna or Jenny was her name, and the hallucinations of the tiger made him want to get rid of her so that he and Jamie will remain the only "little J's" in the family.

There was also a scene where the big brother wanted to runaway because he was so angry. Or maybe this 2as the younger brother. Either way, he took money from his brother's birthday and savings and attempted to run away.

I do not remember the ending. I hope someone out there can help me find this book.

[[EDIT: Turns out it wasn't a tiger, but a lion! The older brother is named Josh and the book is "Catcall" by Linda Newbery. Thank you to all who spent their time helping me, and thank you to the person who found it.]]

[Kris]

Mattie, about how old are the two brothers? Definitely a tiger and not, say, a panther?

What's the tone - fantasy, horror, coming-of-age, etc.?

Do you remember the cover image?

Location - country, region, big city/small town?

[Ayshe]

Catcall by Linda Newbery?

[Mattie]

Kris wrote: "Mattie, about how old are the two brothers? Definitely a tiger and not, say, a panther?

What's the tone - fantasy, horror, coming-of-age, etc.?

Do you remember the cover image?

Location - countr..."

I don't remember their exact ages, but the older one was probably in middle school and up while Jamie was in elementary. Sorry. And maybe not a tiger. All I know is that it was a big cat. I assume tiger because the cover had an eye one the cover with black around it. The location I don't know either, but there are subways so it has to be a rather large city.

[Mattie]

Ayshe wrote: "Catcall by Linda Newbery? I"

Wow, you found it again! That is the third time you have helped me, Ayshe, thank you!