I think it's meant to say
"I machoke you while I Beedril in you. Yeah I'm gonna Raichu like a little Horsea right in the ash and cum until I seal it shut and you squirtle all over me.
It's kind of a poor joke IMO
you got all the names right, but I think you have to play around with them a little to make the joke work better:
I'mma choke you while I be drillin' you. Yeah I'm gonna ride you like a horse (or whore, see) right in the ass and cum until I seal it shut and you squirt all over me.
it's a bit of a stretch, but it works
I feel a bit dirty putting all that on UKMix, though...