Kari, the Elephant by Dhan Gopal Mukerdji illustrated by Zdenek Burian

Dhan Gopal Mukerji, Kari, the Elephant was written in 1922.  You can name it an old-school boys adventure novel.
The English edition was illustrated by J.E. Allen, a pulpillustrator.

The Czech edition with the illustrations by Zdenek Burian was published in 1936.

I was nine years old  and could reach his back if I stood on tiptoe.

I came to the surface of the water to take my breath and there Kari was standing, his feet planted

into the sand bank and his trunk strechted out like a hand waiting for mine. I dove down again and pulled the body of the drowing boy to the surface.

...he waved his trunk at me and then plunged into the other elephant. The whole herd stood around  and watched the fight...

One day about two o' clock, we saw him standing on a rock across the river, looking at the village.

...then with a leap the tiger was by the side of the elephant...

...I saw herds of elephants go into the water to bathe. They did not make the slightest sound; their bodies sank into the water as clouds dip into the sunset.

He would pull heavy logs out of the forest into the open, lift the lighter ones with his trunk and pile them up, one on top of the other.

The first thing he did was to go and put his foot on the automobile of the chief engineer, which happened to be standing outside of the shed. In a few minutes there was nothing but a mass of twisted steel on the ground, over which the elepant danced in anger.