It is a stage one Pokémon, that evolves from the basic Pokémon, Clauncher.
Clawitzer is essentially a Clauncher that has developed a larger claw/gun on its right side. It resembles a howitzer cannon (hence the -itzer suffix in the name). Both Pokémon are crustacean looking creatures that resemble shrimp.
Being water-type, it is only weak to Electric and Grass-type moves, while being resistant to Steel, Fire, Water, and Ice-Type attacks.
With its large claw shaped cannon, it can use moves such as Aqua Jet, Vice Grip, and Crab Hammer.
Clawitzer Pokémon Cards
This Pokémon has a few different cards from various series. It even has its own “Break” card.
All of the cards are water-type.
The Break Card evolves from your normal Clawitzer card and retains the attacks, abilities, resistance, weakness, and retreat cost of the card it evolved from. It gains more HP and a new attack. This new attack is Lock-On. This is a pretty handy move, as it doesn’t allow the opponent’s Pokémon to retreat and increases the damage done by 120. If you have the Crabhammer move, you will do 180 damage, not including any weakness or resistance.
It also comes in shiny form!
The shiny version is red, instead of blue. It can be found in the generation VI and VII games.
There is currently not a shiny version in Pokémon GO.