Tracey's Marill (Japanese: ケンジのマリルKenji's Maril) was one of the two Pokémon owned by Tracey Sketchit before he met Ash in the Orange Islands, and the second seen in his possession.
Marill was first called upon in The Crystal Onix to help locate the mythical Crystal Onix using its superior hearing abilities after Venonat failed to locate it with its sight. In seconds, Marill picked up on Onix's voice and led the group to its secret den on the other side of Sunburst Island. As a WaterPokémon, it was also able to find Onix hiding underwater.
On the day that Tracey announced that he would leave the group to be Professor Oak's assistant, he used Marill to help send Team Rocket blasting off after Scyther had rescued Pikachu from them. The following day, it was seen with Tracey and its teammates as they saw Ash, Misty, and Brock off as they departed for Johto.
In Bulbasaur... the Ambassador!, Marill helped with the crisis at Professor Oak's Laboratory by breaking up a fight between the Water and Grass Pokémon. It later sensed an underground source of water that could be used to construct a new lake and helped soften the earth so it could be dug up.
Marill ready to battle alongside its child, Azurill
Marill hasn't been seen much since Tracey arrived in Pallet Town. However, it produced the Egg that hatched into Misty's Azurill. The two battled alongside each other in The Right Place and the Right Mime, firing dual Water Gun attacks at Team Rocket after they had tried to make off with the Pokémon at Professor Oak's laboratory.
Generally, Marill is a friendly Pokémon with nurturing instincts. While the group was on a deserted island in A Way Off Day Off, it used its tail to entertain Togepi. Marill is also generally obedient unless faced with a big and scary opponent, as seen in In the Pink. In such instances, Marill will jump in Tracey's arms for protection.
Marill is the only one of Tracey's Pokémon that seems to be used both for battling and for Pokémon watching. In the former case, it was called out to battle Team Rocket in Stage Fight! and The Rivalry Revival. In the latter case, its ears can hear Pokémon from far away and locate where the Pokémon are found. Tracey also used it to help find Ash's Pikachu and Misty's Togepi when separated from their Trainers.
