They show up in the Aether Revolt ones, but for a few months there nobody had a specially labeled token to denote their current energy count
For each fellowship vote, the voter chooses a creature they control
Not only does this assist players who are falling behind in the game to garner political favour, Gor Muldrak provides you and your permanents with protection from these tokens, so opponents have little to no incentive to attack you with them
Notably, that +1 ability could create a single bug token, but if the cards in your deck are all lined up just so (and you happen to be running a lot of insects) it could create an unstoppable horde - and super early in the game too
Transform cards become even more cumbersome when their flip condition is like threading the needle
So while some decks might struggle to produce a big payoff from an X spell, green strategies are often well suited to produce lots of mana in a short amount of time, allowing cards like Invasion of Ikoria to suddenly apply pressure with whatever creature is going to be the best solution to a given situation