The Kraken has a bite attack which has the following rules:
Bite: Melee Weapon Attack: +17 to hit, reach 5 ft., one target. Hit: 23 (3d8 + 10) piercing damage. If the target is a Large or smaller creature Grappled by the kraken, that creature is swallowed, and the grapple ends. While swallowed, the creature is Blinded and Restrained, it has total cover against attacks and other Effects outside the kraken, and it takes 42 (12d6) acid damage at the start of each of the kraken's turns. If the kraken takes 50 damage or more on a single turn from a creature inside it, the kraken must succeed on a DC 25 Constitution saving throw at the end of that turn or regurgitate all swallowed creatures, which fall prone in a space within 10 feet of the kraken. If the kraken dies, a swallowed creature is no longer Restrained by it and can escape from the corpse using 15 feet of Movement, exiting prone.
The grapple being mentioned comes from its tentacle attack:
Tentacle: Melee Weapon Attack: +17 to hit, reach 30 ft., one target. Hit: 20 (3d6 + 10) bludgeoning damage, and the target is Grappled (escape DC 18). Until this grapple ends, the target is Restrained. The kraken has ten tentacles, each of which can grapple one target.
The tentacle attack has a range of 30 feet though while the bite has a range of 5 feet. I don't know of any rules saying a creature with a reach attack that can grapple a target can also drag it closer. Does that mean the Kraken can only attempt to use its Bite attack if the target happens to have been grappled while it is only 5 feet away?