Black Swamp Toad

Amphibious. The toad can breathe air and water.

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

Magical Mucus. The toads slimy skin is covered in a mucus it secretes, this mucus in poisonous and causes hallucinations when it makes contact with other creatures skin. When the creature is affected by it they must make a dc 16 con saving throw, if they fail they are considered poisoned and begin to hallucinate (severity at DMs discretion). 

Burrow Nests.  The Toads prefer to sleep burrowed into the ground or where ever they can keep themselves covered. they can dig down to 10ft to keep themselves safe. this can be don as a reaction.

Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 7 (1d10 + 2) piercing damage plus 5 (1d10) poison damage, and the target is grappled (escape DC 13). Until this grapple ends, the target is restrained, and the toad can't bite another target.

Swallow. The toad makes one bite attack against a Medium or smaller target it is grappling. If the attack hits, the target is swallowed, and the grapple ends. The swallowed target is blinded and restrained, it has total cover against attacks and other effects outside the toad, and it takes 10 (3d6) acid damage at the start of each of the toad's turns. The toad can have only one target swallowed at a time. If the toad dies, a swallowed creature is no longer restrained by it and can escape from the corpse using 5 feet of movement, exiting prone.

Poison spit. The toad can use an action to spit out a glob of poisonous mucus at a creature up to 20ft away. The creature must make a dc 16 dex saving throw, on success they take no affect, on failure they take 1d8 poison damage and must make a dc 15 con saving throw. if they fail the con throw they are considered poisoned.

Attack of opportunity. if a creature leaves the toads attack range it may make a bite attack against them. 

Burrow Nests.  The Toads prefer to sleep burrowed into the ground or where ever they can keep themselves covered. they can dig down to 10ft to keep themselves safe. this Gives them a +5 to their ac until they resurface. They also automatically succeed on Dex saving throws unless the attack is directly aimed into their hole.