Bloater

Keen Hearing. The Bloater has advantage on Wisdom (Perception) checks that rely on hearing.

Echolocalization. The Bloater is [condition]blinded[/blinded], but still can see with its blindsight.

Death Spores. When the Bloater dies, the fungi in it body starts to spread a long the floor, walls, or ceiling that the body is touching. After 1 hour of the death of the Bloater, it starts to spread yellow/orange spores. If a creature breath the spores, the creature has the effect of Infection trait.

Infection. The Bloater can bite, but it won't. The creature become poisoned if breath its Death Spores. The condition lasts until the affected creature, or other one, use some sort of spell (lesser restoration, for exemple), cut off the limb with the bite, drink some kind of antidote, finding, or crafting the cure to end the condition. While [condition]poisoned[/condition, the creature must repeat the saving throw every 24 hours, with 3 failures, the creature become a Runner. Succeeses do not end this effect or the condition.

Grappling Slam. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 21 (4d8 + 5) bludgeoning damage. If a creature is hit by two grappling slams, it's grappled and, until the grapple ends, the creature is also restrained. At the end of the grappled creature, it can make a Strength saving throw DC17 to end the condition.

Executioner Attack. The bloater can only attack a grappled, paralyzed, prone, restrained, or stunned creature. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 21 (8d8 + 5). If a creature drops to 0 Hit Points by this action, the Bloater keeps grappling the it and dilacerate its body. If the creature can make death saving throws, the bloater still attack that creature, if it still grappled.

Spore Bomb (Recharge 5–6). Range: 30ft. The Bloater rips a shimmering piece of fungus from its body and hurls it in a point within 30ft from itself. The piece explodes when touchs something solid in a burst of acid spores. Choose a point within range. Each creature that starts its turn within 10ft. of the explosion and isn't infected with the fungus infection, need to succeed in a Constituition saving throw or takes 16 (4d8) acid damage. The spores remain for until the start of the next Bloater's turn.