gentle giant
Someone who is very large and strong but has a quiet and gentle nature. At first, I was afraid of the big, burly man covered in tattoos, but when I saw him rescue that kitten from the tree, I realized he was just a gentle giant.
be as gentle as a lamb
To be pleasant, caring, and calm. My rambunctious son is as gentle as a lamb with our cat. Mr. Stewart may seem crotchety, but he's as gentle as a lamb—he's actually helped me carry my groceries many times.
(as) gentle as a lamb
Pleasant, caring, and calm. My rambunctious son is as gentle as a lamb with our cat. Mr. Stewart may seem crotchety, but he's as gentle as a lamb—he's actually helped me carry my groceries many times.