Papelucho, who has always been fascinated by aliens, decides to catch one and sets a trap. Amazingly it succeeds, and the lost Martian child Det ends up living through Papelucho, with hilarious consequences. The two build a spaceship and travel to Mars, only to escape back to Earth again after the Great Leader of Mars threatens to eat them. Det eventually takes over the body of Papelucho's dog, Choclo, but when Choclo's health is put at risk Papelucho has a difficult decision to make.
| Actor | Role |
|---|---|
 Marina HuertaPapelucho (voice) | Papelucho (voice) |
| AAna Paula FogartyJi (voice) | Ji (voice) |
 Adrián FogartyChoclo (voice) | Choclo (voice) |
 Mario CastañedaPapá (voice) | Papá (voice) |
| HHugo NúñezMarciano 1 (voice) | Marciano 1 (voice) |
| BBardo MirandaMarciano 2 (voice) | Marciano 2 (voice) |
 Leyla RangelDet | Det |
| MMaggie VeraMamá | Mamá |
| NNallely SolísDomotila | Domotila |
 Carlos del CampoChuleta Pardo | Chuleta Pardo |
| LLuis A. PadillaSr. Perrera | Sr. Perrera |
| OOlga HnideyViejita (1) | Viejita (1) |
| PPaty HannidezViejita (2) | Viejita (2) |
| GGerardo VásquezCarabinero | Carabinero |
 Víctor DelgadoTed | Ted |
| JJosé María NegriEnfermero | Enfermero |
 Rogelio GuerraDoctor | Doctor |
| QQueta Calderónmamá de Tita | mamá de Tita |
| MMiguel Ángel LealVoceador | Voceador |
| JJosé Juan FogartyGato | Gato |
| RRebeca GómezSra. Rudecinda / Alumno | Sra. Rudecinda / Alumno |
| RRebeca ManríquezDoña Rosa | Doña Rosa |
 Ricardo BautistaMotociclista | Motociclista |
| EErika EdwardsPerra | Perra |
| DDoris VargasSra. Sofis | Sra. Sofis |
| MMario AldanaChofer | Chofer |
| LLupita LealAlumno | Alumno |