This horrifying plant Pokémon attracts prey with aromatic honey, then melts them in its mouth.
– Pokemon Silver Pokedex
Victreebel is based on a carnivorous pitcher plant. Its mouth has been moved to above its eyes. Its Pokedex entries are pretty sinister, saying how it swallows its prey and dissolves it in its mouth.
In the anime, James had a Victreebel; it ended up leaving him because it fell in love with another Victreebel. Every time Victreebel comes out of its Pokeball, the first thing it does is to try to eat James’ head. I think it does it out of affection for James and for comedic effect, but considering what its Pokedex entries say about its mouth being able to melt prey…
Stat-wise, it has good Attack and Sp Attack, but its other stats are pretty mediocre. Though it has the ability Chlorophyll, which doubles speed in sun (raising its speed to 140), so it could be a pretty good mixed attacker on a sun team.