Leo's little brother is...

[caggie3]

Eli (Short for Elias or Elijah)
Beau
Dominic (love full name but dislike Dom so maybe not a good idea )

Any other suggestions?

Benedict
Gregory
Francis
Xavier
Iggy!

My immediate thought was Rex! Or max?

I have a Leo who’s middle name is Elliot. His brother is Isaac

Max

Noah
Jude
Connor
Ollie
Alex
Harry
Finn
Jack
Rory

Seth

Freddy

Ralph

Isaac
Francis
Felix
Thaddeus
Henry