When the isonade's bite attack hits a target grappled from a previous bite attack, the target is also swallowed. The grapple ends, but the target is blinded and restrained, it has total cover against attacks and other effects outside the isonade, and it takes 36 (8d8) acid damage at the start of each of the isonade's turns. An isonade can have two Large, four Medium, or six Small creatures swallowed at a time. If the isonade takes 40 damage or more from a swallowed creature in a single turn, it must succeed on a DC 20 Constitution saving throw or regurgitate all swallowed creatures, which fall prone within 10 feet of the isonade. If the isonade dies, a swallowed creature is no longer restrained by it and can escape by using 20 feet of movement, exiting prone.