Here is a pocket ants tierlist

Best creatures:

S-tier (best creatures):

Frog - Tanky, has fast attack rate deals a good amount of damage, with its skill Fly Eater being able to one hit kill every flying creature (hornets, dragonflies, wasps) in one hit no matter how much health they have.

Crab - Tanky, attacks slowly but deals the highest damage out of all creatures, has an AoE attack that can damage multiple creatures and wipe out ants in this area.

Basic Ant Units - They die in only 1 hit, but if you are able to distract the enemy creatures with a Rhinoceros beetle or Chrysantemum, they can be used to kill insects super quickly because of their strength in numbers. Do not keep them nearby AoE creatures like crab, rhinoceros or bombardiers or your whole army can die.

A-tier (really good creatures):

Centipede - Has a good amount of health, high attack rate and decent damage, but slow speed. Can withstand a lot of hits and take out individual ants in a decent speed, but they have slow speed and can only attack individual targets instead of AoE like crabs or frogs.

Scorpion - Has a mid amount of health, but it has a high attack rate, fast movement, decent damage and can take out ants quickly.

B-tier (situationally useful, good as support)

Rhinoceros Beetle - Really tanky, this insect is slow, deals little to no damage and has a slow attack rate, but it is really good to bait creatures to group in one place and stun them with chrysantemum, tanky to withstand a lot of hits while other insects attack, and wipe out a lot of ants in its area with the AoE attack.

Butterfly - Fragile, it can heal ally insects within an area and cannot be hit by ground creatures. Good for early game where insects receive much more healing because of their low health, but becomes less useful later in game because of high health insects.

Tarantula - Decent health, slow attack rate, decent damage and mediocre speed. It's a decent creature to take in battles but its heavily outclassed by creatures like centipedes, scorpions, crabs and frogs.

Bombardier beetles - Good health, slow attack rate, little to no damage and slow speed. It's good in defense, as it can wipe out armies of enemy ants and tank a lot of damage, but it's useless in raiding as its slow, weak and its spray doesnt take out much ants compared to defense.

Asian Giant Hornet - They're really useful early game, but once you get to the rank where enemies have frogs, they become useless since they can be instantly killed by frogs.

C-tier (Weak, outclassed):

Tiger beetle - Fragile health, good attack rate and decent damage. They're useful early-game, but their rarity and low health makes them not that useful.

Praying mantis - Fragile health, mediocre attack rate, decent damage and mediocre speed. They're only decent really early game, but they are heavily outclassed later in game.

F-tier (Avoid):

Dragonfly - Fragile health compared to other fliers, mediocre damage, its only niche is being fast but thats about it, its REALLY HEAVILY outclassed by Asian Giant Hornets and event fliers, and it's generally really weak so you should focus on better creatures than the dragonfly.