Pokemon name meaning:
野菜 yasai – vegetable
柳 yanagi – willow tree
Ape – English word
“Ape” transliterated into katakana of course ends in “pu”. The small ッ(which becomes the English double p) is a slight mystery, possibly added for reasons of euphony. ヤナッキー (Yanakkie) also has a small ッ before the last syllable.
This is less problematic in Japanese, since in English a doubled p automatically gives the preceding vowel a short pronunciation (app rather than ape). This is not the case in Japanese. In katakana “ape” would transliterate to エープ ēpu, so it is really only the プ pu that belongs to “ape”. However ップ does not imply a short preceding vowel-sound to the Japanese ear the way ppu does to an English ear.