Leo (レオ) is one of the mascots of team Saitama Seibu Lions from Nippon Professional Baseball.
He has a sister called Lina, who is also a mascot of the team.

Not to be confused with Kimba the White Lion, although he was also designed by Osamu Tezuka.
You will be forgiven if you do confuse him with Kimba, though.
Because he is basically an anthrofied version of Kimba. LOL