Percy Jackson and the Olympians: Legends

Leo looks like a "Latino Santa's elf," with curly black hair, dark brown eyes, a cheerful, elf-like face, normally with a mischievous and impish smile, and a diminutive stature with a slim and relatively scrawny build. He is said to be very short, implied to be between Piper and Hazel in stature. Leo's most notable trait is that he has a look in his eyes that makes him look not only like a troublemaker, but also like he has taken much more caffeine than the normal limit; this could be linked to his ADHD, although he is described as being seriously ADHD even by demigod standards.

Leo is mischievous, flirty, upbeat, resourceful, eccentric, and impulsive, and loves to tell jokes constantly, even if they aren't particularly funny. He prides himself on being the 'class clown' and pulling pranks on those around him. Leo is genuinely very intelligent and honest and cares about his friends and found family. Being bullied growing up taught him to adapt and entertain even under pressure, as making his enemies or peers laugh prevented them from attacking him. He is also shown to be incredibly brave and selfless, willing to sacrifice himself to save his friends and stop Gaea. He is said to be sensitive about his size and occasionally makes self-deprecating jokes about it. Even with his mischievous personality, Leo is also a leader, as he is the counselor of the Hephaestus cabin and a commander on the Argo II.

Following the defeat of Gaia, Leo and his mechanical dragon, Festus, embarked on numerous adventures, aiding demigods and mortals alike. His resourcefulness and engineering genius led him to create groundbreaking inventions that improved life at camp and beyond. Leo also established a workshop where he taught young demigods the art of crafting and mechanics, passing down his knowledge and ensuring that his legacy would continue.