Complete the indicated task to unlock the corresponding bot.

Hummingbird: Get a "B" rank in Egypt (Bronze Cup).
Spider: Complete the Silver Cup.
Boulder monster truck: Gen an "S" rank in all tracks in Mirror mode.

Unlock Super Excite mode and qualify for "Lifetime" rank. Then pay the indicated amount of stars to unlock the corresponding bot.

Hummingbird: 2,500 stars.
Mantis: 2,500 stars.
Mouse: 2,500 stars.
Centipede: 5,000 stars.
Spider: 5,000 stars.
Lizard: 10,000 stars.
Crab: 10,000 stars.
Roach: 10,000 stars.
Scorpion: 15,000 stars
Wasp: 17,000 stars.
Lobster: 19,000 stars.
Ant: 21,000 stars.
Cockroach: 23,000 stars.
Gecko: 25,000 stars.
Squid: 27,000 stars.