Omanyte

Omanyte is a great Pokemon in Little Cup due to its excellent movepool and stats. Due to its ability, Swift Swim, Omanyte can be a powerful sweeper underneath rain, while also posing a threat outside of it. With moves such as Hydro Pump, Earth Power, Ancient Power, Spikes, Toxic Spikes, and Stealth Rock, Omanyte can serve both as an offensive or defensive threat. Omanyte still has its faults, though, most notable is its sub-par Speed stat. Not to mention that Omanyte's main STAB move, Hydro Pump, is a common immunity in Little Cup. Pokemon such as Croagunk can switch in with impunity and OHKO Omanyte with Vacuum Wave.