Amphibious.

The croaker can breathe air and water.

Speak with Frogs and Toads.

The croaker can communicate simple concepts to frogs and toads when it speaks in Bullywug.

Standing Leap.

The croaker's long jump is up to 20 feet and its high jump is up to 10 feet, with or without a running start.

Swamp Camouflage.

The croaker has advantage on Dexterity (Stealth) checks made to hide in swampy terrain.

Actions

Spear.

Melee or Ranged Weapon Attack: +4 to hit, reach 5 ft. or range 20/60 ft., one target. Hit: 5 (1d6 + 2) piercing damage, or 6 (1d8 + 2) piercing damage if used with two hands to make a melee attack.

Bite.

Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 5 (1d6 + 2) piercing damage.

Glaaar-pat (3/Day).

The croaker sings a song of marshy doom. Each chosen creature within 30 feet of the croaker that can hear the song must make a DC 12 Wisdom saving throw, taking 9 (2d8) psychic damage on a failed save, or half as much damage on a successful one. A creature that fails this saving throw also has disadvantage on Constitution saving throws until the end of its next turn.

Rooooo-glog (1/Day).

The croaker sings an ode to an elder froghemoth. Each bullywug within 30 feet of the croaker that can hear the song gains 10 temporary hit points.

Bullywug Croaker