In the anime, called Attack on Titan, the primary antagonists are these huge, humanoid creatures, called titans.
Titans have sizes between 15 and 4 meters. Larger titans aren't unknown, but they splatter, more precisely, they nuke when hitting the ground.
The reason why smaller titans don't nuke the place when falling from 50 meters high, nor sink into the ground, is explained with an all-around low density. So, the tissues of a titan have low density.
Hange Zoë, for instance, kicks one's head around like a football in Ilse's journal (OVA), though she did the same with a heavy table, so keep that in mind.
Now, all the weird * beep * aside that happens later in the show, is it actually possible for a creature's various tissues to have very low densities (I see the most problem with muscle tissues and tendons) without impairing their function?