Some intitial ideas. Note: These matchups are based on the idea of CAP being a special-attacking grass + ice/water type with a speed stat between base 70 (Cloyster's speed) and base 85 (Articuno's speed).
Tauros - Losing: Since CAP will be slower than Tauros and probably won't be the bulkiest, I don't imagine it'll be able to switch in and take out Tauros.
Snorlax - Even: It'll outspeed lax and threaten it with strong special attacks, but can't take many of it's body slams
Chansey - Losing: Since CAP is primarily gonna be a special attacker, I don't imagine it beating Chansey
Starmie - Even: I imagine this will probably be like Victreebel's matchup, in the sense that it'll lose if Mie isn't paralyzed, but will win if Mie is paralyzed
Exeggutor - Depends on type: If it's grass/ice it'll have a good MU against Eggy, if it's grass/water not so much.
Alakazam - Losing/Even: Alakazam's high special will most likely be able to take the special attacks, while dishing out heavy special damage in return, but CAP can probably deal with a weakened Alakazam
Zapdos - Losing/Even: If CAP is an Ice-Type it Threatens Zapdos with STAB Ice moves, but regardless of type, it'll be outsped and threatened by Drill Peck.
Rhydon - Winning: Grass beats Rock, pretty self-explanatory
Cloyster- Winning: Lol
Jynx - Even: This one's pretty interesting imo: It'll be slower than Jynx most and it'll be hit Neutrally with Blizzards while threatening with Razor Leafs in return.
Gengar - Even: Another interesting one, Gengar's high special and grass resistance will help here, but it doesn't threaten CAP offensively that much in return (apart from sleep of course)
Slowbro - Winning: Gets destroyed by Razor Leaf
Articuno - Losing: Lol
Lapras - Winning: If Cloy has a hard time against CAP, then Lapras will also probably struggle.
Victreebel - Depends on Type: See Exeggutor
Persian - Losing: Similar to Tauros, CAP struggle to switch into Persian's slash
Moltres - Depends on Type: Will be Winning/Even if Grass/Water, will be losing if Grass/Ice
Dragonite - Depends on Type and Speed: Fast Grass/Ice can easily take on Dragonite, while other typings will have a shakier matchup
Golem - Winning: See Rhydon
Porygon - Winning: Razor Leaf will likely 2HKO Porygon