Homebrew:Swarm of frogs
Swarm of Frogs can be conjured by a feature of Kobold Engineer, homebrew content from Tasha's Crucible of Everything Else volume 2.

Medium swarm of Tiny beasts, unaligned
Armor Class 11
Hit Points 21 (6d8 - 6)
Speed 20 ft., swim 20 ft.
Roll initiative! +1
STR
DEX
CON
INT
WIS
CHA
7 (-2)
13 (+1)
8 (-1)
1 (-5)
8 (-1)
3 (-4)
Damage Resistances bludgeoning, piercing, slashing
Condition Immunities charmed, frightened, grappled, paralyzed, petrified, prone, restrained, stunned
Skills Perception +1, Stealth +3
Senses Darkvision 30 ft., Passive Perception 11
Languages –
Amphibious. The swarm can breathe air and water.
Slimy and Sticky. A Large or smaller creature occupying the same space as the swarm has disadvantage on weapon attacks.
Standing Leap. The swarm's long jump is up to 10 feet and its high jump up to 5 feet, with or without a running start.
Swarm. The swarm can occupy another creature's space and vice versa, and the swarm can move through any opening large enough for a Tiny frog. The swarm can't regain hit points or gain temporary hit points.