Croconaw in depth
Alligates, or the crocodile that bites its own name
The Japanese name, アリゲイツ, comes from “alligator” with no attempt to hide it. The English name crosses crocodile with gnaw, and that is the summary of the whole design: a crocodile defined by what it does with its jaw. An artist's curiosity — of the 48 fangs mentioned by the Pokédex, only six can be made out in the artwork: the two poking out from the lower corners even with its mouth closed, plus the four on the visible side. The rest exist in the text and nowhere else.
The red spikes are this stage's own contribution. The baby does not have them and the final evolution does not keep them in full, making the middle stage the most decorated of the three, which is unusual for a starter line.
Twelve levels and two moves
The stretch spent as Croconaw is short and fairly poor in terms of level-up moves. Between 18 and 30, it gets only two new attacks: Ice Fang at 21 and Flail at 24, the latter with variable power based on how much health it has left, which is exactly the opposite of what a Pokémon with 65 HP wants. Crunch appears right at level 30, the same level at which it evolves, so in practice you enjoy it as Feraligatr.
Ice Fang is the main reason not to bench it. None of Johto's Gym Leaders uses a type weak to Water, meaning that region's Water starter gets through the adventure without a free advantage, and the Ice attack at level 21 is what gives it a real role against the dragons at the end. Water Gun and Scratch, learned at 1, become obsolete long before then; Waterfall and Surf from TMs are the natural replacements.
Compared with the other middle stages
Compared with Marshtomp, which gains a second type at its middle stage and an immunity along with it, nothing changes here: pure Water from start to finish. Compared with Wartortle, which fills the same spot in Kanto, the spread is different — one leans towards defense and durability, while this one focuses on physical Attack and biting, with 80 in the two stats that matter to it and an EV yield of 1 Attack and 1 Defense, consistent with the rest.
Its TM list is broader than its reputation suggests: Swords Dance, Dragon Dance, Ice Punch, Brick Break, Dig, Rock Slide and Focus Punch. None of that fixes the underlying Speed problem, but it explains why it can carry a normal playthrough up to level 30 without running out of things to do.
A minor continuity detail: the Mystic Water that appears as a wild-held item boosts attacks of its own type, making it a convenient source of that item for the rest of the team.