What do you call a cool octopus?
Tenta-cool (tentacle)
The joke plays on the word 'tentacle' by substituting 'cool' to make 'tenta-cool'. It's a pun using the sound similarity.
That's the name of a Pokémon, did you know?
Yeah its in pokemon
...
That's the name of a Pokémon, did you know?
c
Yeah its in pokemon