Boulder/Harold

Cast

 * Boulder as Harold
 * The Chinese Dragon as Hank
 * The Spiteful Breakvan as BoCo
 * George as Derek
 * Percy as Bulgy (Percy and Bulgy both end with "y")
 * James as Jeremy (James and Jeremy both start with "J")
 * Duncan as Salty
 * Bulgy as Bertie
 * Den as Bill
 * Dart as Ben
 * Bulstrode as Trevor
 * Bertie as S. C Ruffey
 * Max as Donald
 * Monty as Douglas
 * D261 as Henry (D261 and Henry are both Green)
 * Madge as Isobella
 * Elizabeth as Madge
 * S. C Ruffey as Whiff
 * Station Master's Wife as Rosie
 * Diesel as Duck (Diesel and Duck both start with "D")
 * Flynn as Toby
 * Paxton as Colin
 * Sir Handel as Splatter
 * Peter Sam as Dodge
 * Rickety (from RWS) as Stanley
 * Splatter as Jack
 * Dodge as Alfie
 * Arry as Byron
 * Bert as Ned
 * Diesel 10 as Kelly
 * Toby as Patrick
 * Stafford as Nelson
 * The Barber as Buster
 * Burke (from TUGS) as Bash (Burke and Bash both start with "B")
 * Blair (from TUGS) as Dash
 * Sidney as Puffa (from TUGS)
 * Caroline as Flora
 * Rusty as Smudger
 * Skarloey as Arry
 * Rheneas as Bert
 * Oscar (from Sesame Street) as Randy Marsh (from South Park)
 * Grudgetta (from Sesame Street) as Sharon Marsh (from South Park)
 * Hector as Ferdinand
 * Smudger as Oliver (Smudger and Oliver both end with "er")
 * Harold as Rocky
 * Jeremy as Gordon
 * Duck as James
 * Mavis as Caroline
 * Gordon as The Spiteful Breakvan
 * Norman as Hiro
 * Ferdinand as D261
 * Lady as Elizabeth
 * Kevin as Hector
 * Stepney as Diesel
 * Stewie Griffin (from Family Guy) as The Foreman
 * Angelica Pickles (from Rugrats) as Miss Jenny
 * Toad as Thomas
 * Molly Mouse (from Skipper & Skeeto) as Emily
 * Trevor as Diesel 10
 * Oliver as Old Stuck-Up (from RWS)
 * Derek as Percy
 * Shirlena (from Tourettes Guy) as Belle
 * Henry as George
 * Wario (from Mario) as Skarloey
 * Waluigi (from Mario) as Rheneas
 * Scruff as Peter Sam
 * Patrick as Duke
 * Nelson as Duncan
 * Whiff as Sir Handel
 * Lizzie Bee (from Skipper & Skeeto) as Daisy
 * Herry Monster (from Sesame Street) as Boomer (from TUGS)
 * Bill as Burke (from TUGS)
 * Ben as Blair (from TUGS)
 * Rocky as Rusty
 * Class 06 as Freddie
 * Flora as Mrs. Percival
 * Winston as Mr. Percival
 * The Foreman as Stafford
 * Miss Jenny as Lady
 * Byron as Stepney
 * Ned as Billy
 * Farnsworth (from The Little Engine That Could) as Sidney
 * The Freight Engine (from The Little Engine That Could (Book)) as Victor
 * Victor as Den
 * Bash as Dart
 * Dash as Norman
 * Zug (from TUGS) as Scruff
 * PT Boomer (from Thomas & The Magic Railroad) as Edward
 * The Angry Policeman as Murdoch