As an action, you can create a vial of liquid with a cricket that continuously expands suspended in it. The vial can be poured on an insect to transform it into a giant version of its natural form. The insect is friendly to you and your companions, and it disappears when it drops to 0 health, when you use another giant insect liquid concoction, or when the concoction ends.
Centipede. A centipede becomes a Giant Centipede.
Spider. A spider becomes a Giant Wolf Spider (+2 damage on bite) or a Giant Spider.
Wasp. A wasp becomes a Giant Wasp.
Other Insects. An insect becomes a Swarm of Insects.
The GM might allow you to choose different targets. For example, if you transform a bee, its giant version might have the same statistics as a giant wasp.
When it attacks, make a melee alchemical attack in place of its attack, but retain the damage and other effects.
As a bonus action on each of your turns, you can verbally command any creature you enlarged with this concoction if the creature is within 90 meters of you (if you control multiple creatures, you can command any or all of them at the same time, issuing the same command to each one). You decide what action the creature will take and where it will move during its next turn, or you can issue a general command, such as to guard a particular chamber or corridor. If you issue no commands, the creature only defends itself against hostile creatures. Once given an order, the creature continues to follow it until its task is complete.
AugmentYou can augment this concoction with the following options, expending catalysts for each option.
You can transform one additional creature for every 1 additional catalyst expended.
Swarm of Poisonous Snakes. You can expend 1 additional catalyst to transform a snake into a Swarm of Poisonous Snakes. You can transform one additional creature for every 2 additional catalysts expended.
Giant Scorpion. You can expend 1 additional catalysts to transform a scorpion into a Giant Scorpion.